Time-Domain Astronomy: A High Energy View · 2018-08-09 · Hernndez, Aitor Ibarra, Eleni Kalfountzou, Jan-Uwe Ness, Richard Saxton, Norbert Schartel, Michael Smith, Ana Willis. Contents

Time-Domain Astronomy:

A High Energy View13−15 June 2018

European Space Astronomy Centre (ESAC)Villafranca del Castillo

Madrid, Spain

A conference organised by the European Space AgencyXMM-Newton Science Operations Centre

ABSTRACT BOOK

Oral Communications and Posters

Edited by

Jan-Uwe Ness

Organising Committees

Scientific Organising Committee

Matteo Bachetti Osservatorio Astronomico di Cagliari, Selargius, ItalyEnrico Bozzo University of Geneva, Versoix, SwitzerlandGuillaume Dubus University Grenoble Alpes, FrancePhil Evans University Leicester, United KingdomPoshak Gandhi University of Southampton, United KingdomMargarita Hernanz Institute of Space Sciences, Barcelona, SpainSera Markoff University of Amsterdam, The NetherlandsAlex Markowitz Nicolaus Copernicus Astronomical Center, PolandYael Naze Universite de Liege, BelgiumFrancesca Panessa Istituto di Astrofisica e Planetologia Spaziali di Roma, ItalyRichard Saxton XMM-Newton Science Operations Centre, Madrid, SpainNorbert Schartel (co-chair) XMM-Newton Science Operations Centre, Madrid, SpainLara Sidoli Istituto di Astrofisica Spaziale e Fisica Cosmica, Milano, ItalyBeate Stelzer University of Tubingen, Germany

Osservatorio Astronomico di Palermo, ItalyJohn Tomsick University of California, Berkeley, USAPeggy Varniere University Paris Diderot, FranceJorn Wilms (chair) University Erlangen-Nurnberg, GermanyAndreas Zezas University of Crete, Greece

Local Organising Committee

Simone Migliari (Chair), Lucia Ballo, Ignacio de la Calle, Jacobo Ebrero, Felix Frst, CristinaHernndez, Aitor Ibarra, Eleni Kalfountzou, Jan-Uwe Ness, Richard Saxton, Norbert Schartel,Michael Smith, Ana Willis.

Contents

1 Invited Speakers 3

High Energy Emission and Its Variability in Young Stellar ObjectsCostanza Argiroffi . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

Understanding accretion in supermassive black hole binariesTamara Bogdanovic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4

An X-ray spectral-timing (re)view of the inner flow around accreting black holesBarbara De Marco . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Variability of strongly magnetized neutron stars and how this helps us to understandthese systems betterFelix Fuerst . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5

Discovery and Opportunity in the X-ray Time DomainDaryl Haggard . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Mapping the Transient Sky with GaiaSimon Hodgkin . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6

Machine Learning and Data Science in the Era of Survey AstronomyDaniela Huppenkothen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Variability in deep fieldsElisabeta Lusso . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7

Astronomy through the kaleidoscopeMatthew Middleton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Fast Radio BurstsEmily Petroff . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8

Can X-ray dust-scattering affect the GRB afterglows?Fabio Pintore, Andrea Tiengo, Sandro Mereghetti, Giacomo Vianello, Ruben Sal-vaterra, Paolo Esposito, Elisa Costantini, Andrea Giuliani, Zelika Bosnjak . . . . 9

How stars and planets interact: a look through the high-energy windowKatja Poppenhaeger . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9

Accretion, ejection and variability in CVs and novaeGloria Sala . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

The complex phenomena of YSOs revealed by their X-ray variabilitySalvatore Sciortino . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10

Multiwavelength studies of gravitational wave sources: physics and phenomenologyNial Tanvir . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

3

Variable cosmic-ray acceleration in eta CarinaeRoland Walter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

2 Statistics, Methods and Tools 13

Global Fit Time Resolved Spectroscopy: Getting the Most from Low Count Rate DataAnton Chernenko . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14

Hunting for Binaries in the Fermi FL8Y List: Timing and Multiwavelength AnalysesRobin Corbet, Laura Chomiuk, Malcolm Coe, Joel Coley, Guillaume Dubus, PhilipEdwards, Pierrick Martin, Vanessa McBride, Jamie Stevens, Jay Strader, Lee Townsend14

EXTraS: Exploring the X-ray Transient and variable SkyAndrea De Luca, Ruben Salvaterra, Andrea Tiengo, Daniele D’Agostino, Mike Wat-son, Frank Haberl, Jorn Wilms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

An X-ray source population study in NGC 7331Ruolan Jin, Albert Kong . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15

Automated detection and analysis of Be X-ray binary outburstsMatthias Kuhnel, Jorn Wilms, Peter Kretschmar, Deborah Baines, Bruno Merin,Jesus Salgado . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16

Tools for Period Searching in AGN in the Era of Big DataSaikruba Krishnan, Alex Markowitz, Aleksander Schwarzenberg-Czerny, Phil Uttley 16

Spectral and Temporal variability in RXTE Data of Mrk 421Giridhar Nandikotkur . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17

HILIGT - an upper limit and flux server for photon-counting instrumentsRichard Saxton, Miguel Descalzo, Guillaume Belanger, Michael Freyberg, PeterKretschmar, Aitor Ibarra, Carlos Gabriel . . . . . . . . . . . . . . . . . . . . . . . 17

Automatic detection of tidal disruption events and other long duration transients inXMM-Newton dataNatalie Webb . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18

3 Variable Multiwavelength Emitters and Multiwavelength Facilities 19

The Kepler/K2 Supernova ExperimentGeert Barentsen, Jessie Dotson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Time Domain X-Ray Astrophysics: ISS/TAOEhud Behar, Jordan Camp . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20

Coordinated Multi-wavelength Observations of Transitional Millisecond PulsarsSlavko Bogdanov, Adam Deller, James Miller-Jones, Amruta Jaodand, Anne Archibald,Jason Hessels, Alessandro Patruno, Caroline D’Angelo, Cees Bassa . . . . . . . . . 21

The e-ASTROGAM space mission for MeV-GeV gamma-ray astrophysicsStefano Ciprini . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21

The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitional statesduring its 2016 outburstMaria Diaz Trigo, Diego Altamirano . . . . . . . . . . . . . . . . . . . . . . . . . . 22

The nature of the soft X-ray excess in AGNChris Done . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22

Studying optical and very-high-energy gamma-ray variability with Imaging AtmosphericCherenkov TelescopesTarek Hassan, Juan Abel Barrio, Ralph Bird, Jose Luis Contreras, Juan Cortina,Michael Daniel, John Hoang, Jamie Holder, Marcos Lopez Moya, Luis Angel Teje-dor, Greg Richards . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Compact binary millisecond pulsars: new views from X-ray and optical variabilityManuel Linares . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23

Magnetar-like Activity and Radio Variability from High Magnetic Field Pulsar J1119-6127Walid Majid, Aaron Pearlman, Thomas Prince . . . . . . . . . . . . . . . . . . . . 24

Challenges of coordination and possible solutionsJan-Uwe Ness, Aitor Ibarra, Celia Sanchez-Fernandez, Erik Kuulkers, Peter Kretschmar,Jesus Salgado, Emilio Salazar, Matthias Ehle, Carlos Gabriel . . . . . . . . . . . . 24

Hardness Ratio cycles in AGN - classifying different states, and the possible XRB con-nectionUria Peretz, Ehud Behar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

Optical precursors to X-ray binary outburstsDavid Russell, Dan Bramich . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25

XMM-Newton study of the symbiotic binary systems in the Draco dwarf spheroidalgalaxySara Saeedi, Manami Sasaki . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Towards the SuperWASP - XMM stellar rotation-activity relationHeidi Thiemann, Andrew Norton . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

Biases in Gamma-ray and MWL timing studies of AGNStefan Wagner . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27

4 Timing from Accretion and Ejection Phenomena 29

Probing the inner accretion region with the deepest XMM-Newton observation of ahighgly variable AGNWilliam Alston, Andrew Fabian, Douglas Buisson, Erin Kara, Michael Parker, AnneLohfink, Phil Uttley, Dan Wilkins, Ciro Pinto, Barbara De Marco, Edward Cackett,Matthew Middleton, Dom Walton, Chris Reynolds, Jiachen Jiang . . . . . . . . . 30

The flickering jet of MAXI J1535-571Maria Cristina Baglio, David Russell . . . . . . . . . . . . . . . . . . . . . . . . . 30

Disk Structure of Cataclysmic Variables and Broadband Noise Characteristics in com-parison with XRBsSolen Balman . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

X-Ray and mm-Wave Monitoring of Radio Quiet AGNsEhud Behar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31

X-Ray Spectrum of RBS 315: Absorption or Intrinsic CurvatureSivan Ben Haim, Ehud Behar . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

IGR J17329-2731: the birth of a symbiotic X-ray binaryEnrico Bozzo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32

Using multiwavelength spectral variability to uncover the accretion structure in AGNDouglas Buisson . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33

Discovery of a new ULX pulsar in NGC 300Stefania Carpano, Frank Haberl, Chandreyee Maitra, Georgios Vasilopoulos . . . 33

23.8 h QPO in the Swift light curve of XMMU J134736.6+173404Stefania Carpano, Chichuan Jin . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34

First evidence of an X-Ray activity cycle on the young solar-analog Epsilon EridanaeMartina Coffaro, Beate Stelzer, Jorge Sanz-Forcada, Christian Schneider, Uwe Wolter,Marco Mittag, Jeffrey Hall, Travis Metcalfe . . . . . . . . . . . . . . . . . . . . . . 34

Morfology of the fast variability in selected AGNs observed by XMM-NewtonAndrej Dobrotka, Maximilian Stremy, Pavol Bezak . . . . . . . . . . . . . . . . . . 35

Variability from weakly magnitized neutron stars in low-mass X-ray binaries to highlymagnitized neutron stars in ultra-luminous X-ray sourcesMehmet Hakan Erkut, Kazim Yavuz Eksi . . . . . . . . . . . . . . . . . . . . . . . 35

Simultaneous Kepler and XMM observations of bright flares in the PleiadesMario Giuseppe Guarcello, Costanza Argiroffi, Jeremy Drake, Ettore Flaccomio,Javier Lopez-Santiago, Giuseppina Micela, Fabio Reale, Salvatore Sciortino, JohnStauffer, Valsamo Antoniou, Julian David Alvarado-Gomez . . . . . . . . . . . . . 36

Phase resolved spectrum analysis of mHz QPOs in 4U 1636-53 using Hilbert-HuangTransformHung-En Hsieh, Yi Chou, Ka-Ho Tse, Yi-Hao Su . . . . . . . . . . . . . . . . . . . 36

Global radio versus bolometric X-ray flux correlation in the black hole X-ray binary GX339–4Nazma Islam, Andrzej Zdziarski . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

Spectral-Timing Models: The Key to XRB AccretionRa’ad Mahmoud, Chris Done . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37

High-density relativistic reflection as the origin of soft and hard X-ray excess in highly-accreting AGNLabani Mallick, William Alston, Michael Parker, Ciro Pinto, Andrew Fabian . . . 38

Complex Circumnuclear Structures in the Radio-Loud AGN Mkn 6 from X-ray Absorp-tion VariabilityAlex Markowitz, Beatriz Mingo, Martin Hardcastle . . . . . . . . . . . . . . . . . 38

Rapid X-ray spectral variability observed in the star forming galaxy MCG–3–58–007Gabriele Matzeu, Valentina Braito, James Reeves, Paola Severgnini, Roberto DellaCeca, Claudia Cicone, Michael Parker, Maria Santos-Lleo, Norbert Schartel . . . . 39

Mildly obscured AGN and the CXB: From averaged properties to individual sourcesChristos Panagiotou, Roland Walter . . . . . . . . . . . . . . . . . . . . . . . . . . 39

The X-ray continuum time-lags and intrinsic coherence in AGNIossif Papadakis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

Rapid variability of ultra-fast outflows and timing prospectsMichael Parker . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 40

The rapid growth of black holes in the early UniverseEdwige Pezzulli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41

Long-term variability of high-mass X-ray binaries with MAXIJose Joaquın Rodes, Tatehiro Mihara, Jose Miguel Torrejon, Mutsumi Sugizaki,Graciela Sanjurjo-Ferrın, Guillermo Bernabeu, Satoshi Nakahira . . . . . . . . . . 41

The Vast Potential of Exoplanet Hunting Satellites for High Energy Time Domain As-trophysicsKrista Lynne Smith . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42

Radiative transfer in the neutron star atmosphere: reflection modelEkaterina Sokolova-Lapa, Sebastian Falkner, Jorn Wilms, Fritz-Walter Schwarm . 42

Energy dependent timing studies of the low-hard state of black hole X-ray binaries withXMM-NewtonHolger Stiele, Albert Kong . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Super-Eddington X-ray pulsars in the Magellanic CloudsLee Townsend . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43

Fast quasi-periodic oscillations in magnetic cataclysmic variablesLucile Van Box Som, Jean-Marc Bonnet-Bidaud, Clotilde Busschaert, Andrea Cia-rdi, Emeric Falize, Martine Mouchet . . . . . . . . . . . . . . . . . . . . . . . . . . 44

Living on the edge: the RWI in accretion disk around Kerr Black holePeggy Varniere, Frederic Vincent, Fabien Casse . . . . . . . . . . . . . . . . . . . 44

NOVAs: a Numerical Observatory of Violent Accreting systemsPeggy Varniere, Fabien Casse, Frederic Vincent . . . . . . . . . . . . . . . . . . . 45

Multiwavelength variability of GX 339-4 during its 2015 outburst decayFederico Vincentelli, Piergiorgio Casella, Kieran O’Brien, Thomas Maccarone, PhilUttley, Tomaso Belloni, Rob Fender, David Russell, Barbara De Marco, JulienMalzac . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 45

5 Triggers of Variability: Magnetism, Shocks, Companions 47

General Relativity through OJ 287 light curve timingStefano Ciprini, Mauri Valtonen, Staszek Zola, Arti Goyal . . . . . . . . . . . . . 48

Fast X-ray flares and quiescent emission from the quadruple system GT MuscaeLorenzo Ducci, Santina Piraino, Long Ji, Andrea Santangelo, Juergen Schmitt, CarloFerrigno, Enrico Bozzo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48

Is there any Correlation between Radiative Outbursts and Timing Irregularities in Mag-netars?Chin-Ping Hu, C.-Y. Ng . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49

Seven years in the cyclic coronal life of iota HorJorge Sanz-Forcada, Beate Stelzer, Martina Coffaro . . . . . . . . . . . . . . . . . 49

Calibrating the time-evolution of the X-ray emission of M dwarfsBeate Stelzer, Ignasi Ribas, Diego Lorenzo de Oliveira, Laura Venuti, Richard Sax-ton . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

6 Explosive Astrophysics/Fast Astrophysics 51

The Transient High Energy Sky and Early Universe Surveyor (THESEUS)Lorenzo Amati, Paul O’Brien, Diego Gotz, Enrico Bozzo, Christopher Tenzer . . . 52

Coordinated X-ray and Radio Observations of the Repeating Fast Radio Burst FRB121102Slavko Bogdanov, Paul Scholz, Jason Hessels, Ryan Lynch, Laura Spitler, CeesBassa, Geoff Bower, Sarah Burke-Spolaor, Bryan Butler, Shami Chatterjee, JamesCordes, Kelly Gourdji, Victoria Kaspi, Casey Law, Benito Marcote . . . . . . . . 52

Disk-jet alignment in Tidal Disruption Events: hints from Swift J1644+57Sudip Chakraborty, Sudip Bhattacharyya, Chandrachur Chakraborty . . . . . . . 53

Multiple X-ray bursts and the model of a spreading layer of accreting matter over theneutron star surfaceSergei Grebenev, Ivan Chelovekov . . . . . . . . . . . . . . . . . . . . . . . . . . . 53

X-ray observations of Tidal Disruption Events in the era of Time Domain AstronomyErin Kara . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Two Distinct-Absorption X-Ray Components from Type IIn Supernovae: Evidence forAsphericity in the Circumstellar MediumSatoru Katsuda, Keiichi Maeda . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54

Identifying the XMM-Newton slew variable source population and the implication forEinstein ProbeDongyue Li, Richard Saxton, Weimin Yuan . . . . . . . . . . . . . . . . . . . . . . 55

Searching for fast transients in XMM-Newton dataInes Pastor Marazuela, Natalie Webb . . . . . . . . . . . . . . . . . . . . . . . . . 55

Observations of tidal disruption events: past, present and futureRichard Saxton, Andrew Read, Stefanie Komossa, Kate Alexander, Pauline Lira,Iain Steele . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

Fast extragalactic transients in the XMM-Newton archiveAndrea Tiengo, Giovanni Novara, Andrea De Luca, Ruben Salvaterra, AndreaBelfiore, Martino Marelli . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 56

A network of optical telescopes dedicated to the early follow-up of multimessenger triggersDamien Turpin on behalf of the GWAC team, Sarah Antier, Alain Klotz, NicolasLeroy, En-wei Liang, Xiang-Gao Wang, Zi-Gao Dai, Xiang-Yu Wang, Yuan-GuiYang, Bertrand Cordier, Damien Dornic, Bo-Bing Wu, Cyril Lachaud . . . . . . . 57

Name Index 58

Chapter 1

Invited Speakers

4 Invited Speakers

High Energy Emission and Its Variability in Young Stellar Objects

Costanza Argiroffi1,2

1DiFC, University of Palermo2INAF - Osservatorio Astronomico di Palermo

Young stellar objects show a variety of highly energetic phenomena: on the one hand youngstars are characterized by accretion and outflow processes, on the other hand young stars possesshot coronal plasmas in their outer atmosphere. Notably all these phenomena are regulated by theintense stellar magnetic fields. I will show how these phenomena are simultaneously responsiblefor the high energy emission from young stars, and how their individual contributions can beseparated. I will present recent results obtained by pushing to the limit the capabilities of nowadaysX-ray observatories, and by developing detailed MHD models. These results provide fundamentalconstraints on accretion stream properties, accretion geometries, coronal loop dimensions, coronalactivity, and disk irradiation. I will finally discuss what are the open issues that need to beaddressed. Understanding these phenomena will help in comprehending the interplay betweenmagnetic field and matter in young stars, and eventually the exchange of mass, energy, and angularmomentum between the central star and its circumstellar environment.

Understanding accretion in supermassive black hole binaries

Tamara Bogdanovic1

1Georgia Institute of Technology

Supermassive black hole binaries are thought to be a natural product of galactic mergers andgrowth of the large scale structure in the universe. They remain observationally elusive, thusraising a question about characteristic observational signatures associated with these systems.The question of observational signatures is on the other hand intimately related to the nature ofaccretion in supermassive black hole binaries. In my talk I will discuss how the ongoing theoreticalefforts and observational searches contribute to our understanding of accretion and variability insupermassive black hole binaries.

Invited Speakers 5

An X-ray spectral-timing (re)view of the inner flow around accreting black holes

Barbara De Marco1

1N. Copernicus Astronomical Center PAN

X-ray variability is one of the main outcomes of accretion onto black holes. Though its origin isyet to be understood, X-ray variability is the fingerprint of processes occurring close to the centralblack hole, therefore it is a powerful probe of these regions. I will give an overview of results sofar obtained by combining the X-ray timing and spectral information in an effort to further ourunderstanding of the physics and geometry of the accretion flow around accreting black holes.

Variability of strongly magnetized neutron stars and how this helps us tounderstand these systems better

Felix Fuerst11ESA/ESAC

Strongly magnetised neutron stars show periodic and aperiodic variability on many time-scales.By obtaining spectral information on these different time-scales, we can obtain a closer look intothe physics of accretion close to the neutron star and the properties of the accreted material.

I will talk about strong pulsations, i.e., the rotation of the neutron star itself. Over one rotationour view of the accretion column and X-ray producing region changes significantly, providing uson the one hand with different insights into this region, on the other hand, requiring that we haveviewing-angle resolved models to properly describe the physics within the column.

In high-mass X-ray binaries the main source of aperiodic variability is the clumpy stellar wind,which leads to changes in accretion rate (i.e. luminosity) as well as absorption column. Thisvariability allows us to study the behavior of the accretion column as function of luminosity, aswell as allows us to investigate the structure and physical properties of the wind, which we cancompare with winds in isolated stars. I will present new results of the archetypical source Vela X-1with high-resolution spectroscopy and non-LTE stellar atmosphere codes, which provide deeperinsight into the wind parameters.

6 Invited Speakers

Discovery and Opportunity in the X-ray Time Domain

Daryl Haggard1

1McGill University/McGill Space Institute

Ambitious X-ray observatories have enabled a rapid expansion in our knowledge of the X-raytime domain. With state-of-the-art facilities like Chandra, XMM Newton, and Swift performingsurveys over a decade and counting, variability catalogs are increasingly rich. Meanwhile, hightime resolution from the likes of NuSTAR and NICER (and RXTE before them) continue touncover new physics in individual systems. These efforts have lead to the discovery of high-energyEM counterparts to the first binary neutron star merger detected via gravitational waves, a likelypulsar-ULX connection, possible magnetar oscillations, X-ray flares from the closest supermassiveblack hole, Sgr A*, and enabled reverberation mapping of AGN, to name only a few. I will reviewrecent highlights from the X-ray time domain and briefly describe what we hope to achieve withupcoming and proposed X-ray missions.

Mapping the Transient Sky with Gaia

Simon Hodgkin1

1Institute of Astronomy, Cambridge University

Gaia is an ESA cornerstone mission, delivering precision photometry, astrometry, spectropho-tometry, and spectroscopy, all based on regular image-scanning the sky through two telescopes andthe largest focal-plane array (1Gpixel) yet launched. This by design makes the time-domain theheart of Gaia’s scientific requirements and capabilities. Gaia is monitoring the sky with cadencesof seconds (between CCDs), hours (between fields-of-view) and weeks (between visits), with real-time source detection implemented by a fixed, available, and well-understood on-board algorithm.Every Gaia source obtains near-simultaneous spectrophotometry.

The GaiaAlerts system has been running routinely and reliably since January 2016, publishing6 transients per day (see http://gsaweb.ast.cam.ac.uk/alerts/home), using well-defined selectioncriteria. We scan the whole sky exploring into the Galactic plane and crowded regions which aretypically hard to do from the ground. I will describe the challenges we face in searching throughhalf a billion CCD measurements every day to identify and publish Gaias transient events. I willdiscuss the properties of the alerts published to date and highlight some of our most interestingdiscoveries. I will examine the completeness and biases in our selection criteria, and look ahead tofuture improvements in the system, including making the most of Gaias astrometry.

Invited Speakers 7

Machine Learning and Data Science in the Era of Survey Astronomy

Daniela Huppenkothen1

1DIRAC, University of Washington

Across almost all scientific disciplines, the instruments that record our experimental data andthe methods required for storage and data analysis are rapidly increasing in complexity. This hasbeen particularly true for astronomy, where current and future instruments produce data sets ofa size and complexity not accessible with traditional methods. In this talk, I will focus on recentresearch in survey astronomy and present examples of how we can use modern computational tools,especially machine learning, to help us make sense of large-scale time series data sets. I will alsodiscuss advantages and challenges associated with these methods.

Variability in deep fields

Elisabeta Lusso1

1Centre for Extragalactic Astronomy, Department of Physics, Durham University, UK

I will review the latest results on X-ray AGN variability in deep fields from XMM-Newton andChandra and I will present the findings on the variability properties as a function of redshift,and physical parameters such as obscuration, black hole mass, and accretion rate. I will discusshow multi wavelength observations can provide further insights on the disk/corona propertiesand whether simultaneous optical/X-ray observations will help in determining tight correlationsamongst physical parameters. Finally, I will discuss possible applications using these correlationsby enlarging the current samples of AGN in future surveys.

8 Invited Speakers

Astronomy through the kaleidoscope

Matthew Middleton1

1University of Southampton

High energy observations (specifically those in the X-rays) provide a window into extreme en-vironments such as those close to gravitationally compact objects, the formation of stars and evenregions of particle acceleration in the gas giants of our solar system. Whilst compelling insightsare gained by studying in a single band, the picture remains incomplete (and potentially mislead-ing) without the inclusion of data from other bands sampling different physical processes. Thissomewhat obvious statement belies the difficulty inherent in performing such multi-wavelengthcampaigns, especially when they are time-critical (either constrained or requiring near simultane-ity for variability studies). I will review some of the recent exciting multi-wavelength results, someof the difficulties that we face as a community and how we might seek to mitigate these as we moveinto the multi messenger/synoptic era.

Fast Radio Bursts

Emily Petroff1

1ASTRON, Netherlands Institute for Radio Astronomy

Fast radio bursts (FRBs) are quickly becoming a subject of intense interest in time-domainastronomy. FRBs have the exciting potential to be used as cosmological probes of both matter andfundamental parameters, but such studies require large populations. Advances in FRB detectionusing current and next-generation radio telescopes will enable the growth of the population in thenext few years. Real-time discovery of FRBs is now possible with a significant number of FRBsnow detected in real-time. I will discuss the developing strategies for maximising real-time sciencewith FRBs as well as the properties of the growing FRB population. I will also discuss upcomingefforts to detect FRBs across the radio spectrum using a wide range of new and refurbished radiotelescopes around the world and how these discoveries can inform next generation surveys andpave the way for the enormous number of FRB discoveries expected in the SKA era.

Invited Speakers 9

Can X-ray dust-scattering affect the GRB afterglows?

Fabio Pintore1, Andrea Tiengo2, Sandro Mereghetti1, Giacomo Vianello3, Ruben Salvaterra1,Paolo Esposito4, Elisa Costantini5, Andrea Giuliani1, Zelika Bosnjak6

1INAF IASF Milano, Via E. Bassini 15, 20133 Milano, Italy2Scuola Universitaria Superiore IUSS Pavia, Piazza della Vittoria 15, 27100 Pavia, Italy3SLAC National Accelerator Laboratory, Stanford University, Stanford, CA 94305, USA

4Anton Pannekoek Institute for Astronomy, University of Amsterdam, Postbus 94249, 1090-GE Amsterdam,The Netherlands

5SRON Netherlands Institute for Space Research, Sorbonnelaan, 2, 3584-CA, Utrecht, The Netherlands6Faculty of Electrical Engineering and Computing, University of Zagreb, 10000 Zagreb, Croatia

X-ray observatories with good imaging capabilities (as XMM-Newton, Chandra and Swift) haveextensively observed X-ray halos or expanding rings around bright X-ray Galactic binary systems,magnetars and gamma ray bursts (GRBs). Their origin is nowadays firmly associated to thescattering of X-ray photons by the dust-grains of the interstellar medium, located between us andthe source. Recently, X-ray dust-scattering features were found around the afterglow of GRB160623A. Thanks to a XMM-Newton observation of the afterglow, carried out 2 days after theGRB event, it was possible to find evidence of at least six expanding rings (with sizes rangingbetween 2’ and 9’) around its position. The rings were associated to X-ray scattering of theprompt GRB emission by several dust clouds along the line of sight and placed in our Galaxy. Onthe other hand, it is important to note that dust-clouds are expected to be present also in thehost galaxies of GRBS. Hence, dust-scattering effects in the local GRB environments cannot beexcluded, even though it is not possible to resolve them spatially with the current instruments.In this talk, we will discuss the possibility that dust-scattering processes may affect the observedlong-lasting tails of GRB afterglows.

How stars and planets interact: a look through the high-energy window

Katja Poppenhaeger11Queen’s University Belfast, Astrophysics Research Centre

The architecture of many exoplanetary systems is different from the solar system, with exoplan-ets being in close orbits around their host stars and having orbital periods of only a few days. Wecan expect interactions between the star and the exoplanet for such systems that are similar tothe tidal interactions observed in close stellar binary systems. For the exoplanet, tidal interactioncan lead to circularization of its orbit and the synchronization of its rotational and orbital period;additionally, irradiation can even lead to planets having star-like surface temperatures. For thehost star, it has long been speculated if significant angular momentum transfer can take placebetween the planetary orbit and the stellar rotation. Investigating if this can lead to increasedhigh-energy emission from stars, as opposed to their regular coronal evolution, is a challengingtask, as cool stars already display stochastic flaring as a baseline behaviour. I will review differentobservational approaches to identify interactions between stars and planets, and discuss how theyare expected to influence the long-term evolution of star-planet systems.

10 Invited Speakers

Accretion, ejection and variability in CVs and novae

Gloria Sala1,2

1Universitat Politecnica de Catalunya-BarcelonaTech (UPC)2Institut d’Estudis Espacials de Catalunya (IEEC)

Accreting white dwarf binaries show a wide range of timescales of variabilities, from secondsto months and years. Disc instabilities, disc-jet connection and magnetic accretion are present inaccreting white dwarfs, making them interesting laboratories of the accretion and ejection mech-anisms. In addition, the explosive events of nova outbursts involve the massive ejection of theaccreted envelope on top of the white dwarf. Among novae, the subclass of recurrent novae arethought to contain a massive white dwarf. This, in combination with a high outburst frequency,make them good candidates to progenitors of Type Ia supernovae. Novae are luminous X-raysources. Soft X-rays probe the residual nuclear burning, while the ejected shell and/or the ac-cretion disk are the site of harder X-rays. Recently discovered very high gamma-ray emission isthough to be related to particle acceleration in the ejecta. Transient short period oscillations havebeen detected in the soft X-rays of both novae and persistent supersoft sources. Their origin isstill unclear. They may be connected to the rotation of the white dwarf in some cases, but theymay also arise from pulsations in the H-burning envelope.

The complex phenomena of YSOs revealed by their X-ray variability

Salvatore Sciortino1

1INAF/Osservatorio Astronomico di Palermo, Palermo, Italy

X-ray observations of Young Stellar Objects (YSOs) have shown several complex phenomenaat work. In recent years a few programs based on long continuous X-ray, and sporadically onsimultaneous coordinated multi-wavelength, observations have paved the way to our current un-derstanding of the physical processes at work that very likely regulates the interaction betweenthe star and its circumstellar disk. I will present and discuss some recent results based on a novelanalysis of very large flares observed with the Chandra Orion Ultra-deep Pointing (COUP), on thesystematic analysis of a large collection of flares observed with the Coordinated Synoptic Investi-gation of NGC 2264 (CSI 2264) as well as on the Class I YSO Elias 29 in the rho Oph star formingregion whose data have been recently gathered as part of a joint continuous XMM-Newton andNuStar large program.

Invited Speakers 11

Multiwavelength studies of gravitational wave sources: physics and phenomenology

Nial Tanvir11University of Leicester

The electromagnetic detection of events that are also detected as gravitational wave sources haslong been a holy grail of astrophysics, allowing, as it does, determination of redshifts, distanceestimates and characterisation of galactic environments linked to source properties. This ambitionwas finally realised in August 2017 with the discovery of the binary neutron star merger GW170817by LIGO/Virgo, and the subsequent detection its counterpart across the electromagnetic spectrum.I will review what we have learnt about the physics of this event from the pan-chromatic view of thekilonova and also the emission from a relativistic component that led to the initial accompanyinggamma-ray flash. Finally I will consider implications for future studies.

Variable cosmic-ray acceleration in eta Carinae

Roland Walter11University of Geneva

Galactic cosmic-rays are likely produced through Fermi acceleration in supernova remnantshocks and other exotic sources. Identifying the different contributors is fundamental to understandgalactic processes, how Fermi acceleration works in various environments, and the feed-back be-tween cosmic-ray acceleration, galactic magnetic fields and the dynamics of the interstellar medium.Variable sources are fundamental to study particle shock acceleration as the correlated observationsin various energy bands provide key signatures of the physical processes at play. Particle accel-eration in stellar wind collision can be particularly well studied in η Carinae, the most luminousmassive colliding wind binary system of our Galaxy and the first one to have been detected at veryhigh energies without hosting a compact object. Most of the shock power is released on both sidesof the wind collision zone downstream of the wind-collision region. The photon-photon opacitycould also be estimated as < 10−2, excluding a significant effect on the observed GeV spectrum.γ-ray observations can probe the magnetic field and shock acceleration in details. η Carinae couldyield to 1048−49 erg of cosmic-ray acceleration, a number close to the expectation for an averagesupernova remnant.

12 Invited Speakers

Chapter 2

Statistics, Methods and Tools

14 Statistics, Methods and Tools

Global Fit Time Resolved Spectroscopy: Getting the Most from Low Count RateData

Anton Chernenko1

1Space Research Institute

Many transient and variable astrophysical objects are known to manifest variability startingfrom at least sub-millisecond time scales. Even with the most advanced modern experiments,spectroscopy with such a high time resolution is hardly or not possible even for the brightestobjects of their classes.

The use of the Global Fit Analysis (GFA) allows one to investigate spectral variability with thefinest time resolution where traditional spectroscopy techniques fail due low count rate. This isachieved thanks to special assumptions about intrinsic properties of the spectra. With the GFAone could extend spectral analysis to far tails of emission where traditional spectroscopy fails dueto low S/N ratio. Or, to reach by an order of magnitude finer time resolution during brighterperiods of the emission.

In GFA, instead of parameterizing individual spectra and analyzing spectral evolution in termsof numerous individual spectral fit parameters we define a spectral evolution model with a set ofconstant global parameters and just a few (N=1-2) time dependent variables. Besides the timehistories of physically meaningful spectral parameters GFA also allows us to obtain, for each object,a set of global parameters for population studies.

Hunting for Binaries in the Fermi FL8Y List: Timing and Multiwavelength Analyses

Robin Corbet1, Laura Chomiuk2, Malcolm Coe3, Joel Coley4, Guillaume Dubus5, PhilipEdwards6, Pierrick Martin7, Vanessa McBride8, Jamie Stevens6, Jay Strader2, Lee Townsend8

1UMBC/NASA GSFC/MICA2Michigan State3Southampton

4NASA GSFC/NPP5IPAG Grenoble

6CSIRO7IRAP

8Cape Town

The Fermi LAT team recently released the FL8Y list of gamma-ray sources. This contains 5524sources compared to the 3033 in the third Fermi LAT catalog. We are searching for gamma-raybinaries in the FL8Y using a combination of techniques. We construct high signal-to-noise gamma-ray light curves for all sources, then search these for indications of periodic variability that could bethe sign of a binary system. We then employ a multi-wavelength approach including radio, optical,and X-ray to identify counterparts, and search for similar periodic variability at other wavelengths.Our approach previously led to our discovery of the gamma-ray binaries 1FGL J1018.6-5856 andLMC P3. We will report on our search results for the FL8Y list, and the prospects for improvedsearches using the 4FGL catalog which will be a refinement of the FL8Y.

Statistics, Methods and Tools 15

EXTraS: Exploring the X-ray Transient and variable Sky

Andrea De Luca1, Ruben Salvaterra1, Andrea Tiengo2, Daniele D’Agostino3, Mike Watson4,Frank Haberl5, Jorn Wilms6

1INAF/IASF Milano, Milano, Italy2IUSS, Pavia, Italy

3CNR/IMATI, Genova, Italy4University of Leicester, Leicester, UK

5MPG/MPE, Garching, Germany6ECAP, Bamberg, Germany

The EXTraS project extracted all temporal domain information buried in the whole databasecollected by the EPIC cameras onboard the XMM-Newton mission. This included a search andcharacterisation of variability, both periodic and aperiodic, in hundreds of thousands of sourcesspanning more than eight orders of magnitude in time scale and six orders of magnitude in flux,as well as a search for fast transients, missed by standard image analysis. All results and productsof EXTraS are made available to the scientific community through a web public data archive.A dedicated science gateway allows scientists to apply EXTraS pipelines on new observations.EXTraS is the most comprehensive analysis of variability, on the largest ever sample of soft X-ray sources. The resulting archive and tools disclose a very large scientific discovery space tothe community, with applications ranging from the search for rare events to population studies,with impact on the study of virtually all astrophysical source classes. EXTraS, funded withinthe EU/FP7 framework, was carried out by a collaboration including INAF (Italy), IUSS (Italy),CNR/IMATI (Italy), University of Leicester (UK), MPE (Germany) and ECAP (Germany).

An X-ray source population study in NGC 7331

Ruolan Jin1, Albert Kong1

1Institute of Astronomy, National Tsing Hua University

We present Chandra X-ray observations of the nearby spiral galaxy NGC 7331. Fifty-five X-ray point sources with source significance larger than 3 are found within the optical D25 regionaccording to seven Chandra ACIS-S observations taken between 2001 and 2016. The detection limitof our sample is 3.59×1037erg s−1 in the 0.5 – 7.0 keV energy range. Twenty of our detected X-raysources are variables and 3 of the variables are transients. We also find 9 new ultra-luminous X-ray sources (the maximum detected luminosities large than 1×1039erg s−1) comparing to previousstudy. Some of the sources possess a bimodal luminosity-hardness ratio (HR) feature, which isoften observed among X-ray binaries. We also performed spectral fits for 8 sources with highsignal-to-noise ratios as well as the supernova 2014C. The cumulative X-ray luminosity functions(XLF) of point sources can be well described with a power-law with a slope of around -0.99 byusing PyMc3, a Bayesian inference based package, in three different ways: pooling, unpooling andhierarchical. We conclude that neither the variability of the X-ray sources nor the bright outliershas much impact on the XLF of NGC 7331 in fitting with a power-law, especially for a hierarchicalmethod.


Automated detection and analysis of Be X-ray binary outbursts

Matthias Kuhnel1, Jorn Wilms1, Peter Kretschmar2, Deborah Baines2, Bruno Merin2, JesusSalgado2

1Dr. Karl Remeis-observatory & ECAP, University of Erlangen-Nuremberg, Bamberg, Germany2European Space Astronomy Centre (ESAC), Madrid, Spain

We report on the development of an extensive database of Be X-ray binary properties, obser-vations, and long term variability, which will serve as a prototype for connecting archival data ofpointed and monitoring observations from existing and historic missions with source meta data.As an example for meta data, we focus on source activities such as X-ray outbursts and long-termlight curves. We present an automated software pipeline for detecting and characterizing theseoutbursts. During a first step, all monitoring light curves, e.g., as recorded by Swift-BAT andMAXI, are matched against activity criteria. Each detected activity period is then analyzed toderive the outburst properties, such as rise and decline time scale. Once the results have been in-gested into the database, this will enable us, for the first time, to study Be X-ray binary outburstsin a systematic and quantitative way

Tools for Period Searching in AGN in the Era of Big Data

Saikruba Krishnan1, Alex Markowitz1,2, Aleksander Schwarzenberg-Czerny1, Phil Uttley3

1Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland2UC San Diego, Center for Astrophysics and Space Sciences, La Jolla, USA

3Anton Pannekoek Institute of Astronomy, University of Amsterdam, Amsterdam, Netherlands

Active Galactic Nuclei persistently emit across the electromagnetic spectrum and are domi-nated by stochastic, aperiodic emission that is variable on timescales from hours to decades. Thestochastic variability tends to overwhelm any possible periodic signal, preventing us from robustlyconfirming if periodic signals are present in AGN. It has also been seen that pure stochastic rednoise signals spuriously mimic few-cycle periods. Hence in our project we try to account for thered noise properly using different methods (ACF, epoch folding, wavelet analysis and Bayesiananalysis) and test if each method can robustly distinguish between pure red-noise processes andmixtures of a strictly- or quasi-periodic signal (QPO) plus red noise, while pursuing the followingquestions: When the variability process is pure red noise (no QPO present), what is the false-alarmprobability and how does it depend on broadband continuum shape? When there is intrinsicallya mixture of red noise and a QPO, is there a range in detection sensitivity between the variousmethods? How many observed cycles are needed for confirmation of a detection? Here we presentpreliminary results and inferences drawn from analysis in progress.

Statistics, Methods and Tools 17

Spectral and Temporal variability in RXTE Data of Mrk 421

Giridhar Nandikotkur11School of Natural Sciences, Fairleigh Dickinson University, Teaneck, New Jersey, USA

NASAs Rossi X-ray Timing Explorer (RXTE) has provided time-domain data of highest qualityfor several categories of sources. Among the high-frequency peaked BLlac objects, Mrk421 wasobserved numerous times through the 16 years of operation during which the source flared up byseveral orders of magnitude. The three instruments (All Sky Monitor-ASM, Proportional CounterArray-PCA and High Energy X-ray Timing Experiment - HEXTE) on board RXTE observed thesource at different range of wavelengths spanning 2 keV 250 keV. We are conducting an exhaustivestudy of the entire data to investigate various aspects of temporal and spectral variability. Thelight-curves are being analyzed using various statistical techniques to investigate the presence ofinherent timescales of variability and to check if the times scale is unique to the entire range ofwavelength of the satellite. The pattern of spectral hysteresis with flux is being examined as afunction of strength of the flare and the relative position of spectral energy range in relation tothe peak of the synchrotron emission. The data shows indications of self-similarity at multipletimescales on which the data can be binned. Some of the results of this systematic study will bepresented.

HILIGT - an upper limit and flux server for photon-counting instruments

Richard Saxton1, Miguel Descalzo1, Guillaume Belanger2, Michael Freyberg3, Peter Kretschmar1,Aitor Ibarra1, Carlos Gabriel1

1XMM SOC, ESAC, Madrid2INTEGRAL SOC, ESAC, Madrid

3MPE, Garching, Germany

The advent of all-sky facilities, such as Swift, ASASSN, eRosita and LSST has led to a newappreciation of the importance of transient sources in solving outstanding astrophysical questions.Identification and catalogue follow-up of transients has been eased over the last two decades bythe Virtual Observatory but we still lack a tool to provide a seamless, self-consistent, analysis ofall observations made of a particular object by current and historical facilities. HILIGT is a web-based interface which polls individual servers, written for XMM-Newton, INTEGRAL, ROSATand other missions, to find the fluxes, or upper limits, from all observations made of a given target.These measurements are displayed as a table or a time series plot which may be downloaded invarious formats.


Automatic detection of tidal disruption events and other long duration transients inXMM-Newton data

Natalie Webb1

1IRAP, Toulouse, France

XMM-Newton’s large field of view and excellent sensitivity have resulted in hundreds of thou-sands of serendipitous X-ray detections. Whilst their spectra have been widely exploited, theirvariable nature has been little studied. Part of this is due to the way XMM-Newton currentlyoperates, where observations generally have a 12 month proprietary period. It is often too late tofollow-up a serendipitous transient a year after detection. New robust software could be introducedinto the pipeline to automatically identify bright transients that are not the target of the observa-tion. Statistically, hundreds of tidal disruption events (TDEs) have been detected serendipitouslyby XMM-Newton. With prior consent from the PI of the observation, an automatically generatedATEL could alert to a new transient, allowing it to be followed-up within weeks, ideal for TDEsthat are bright for about a year. Over the next decade, hundreds more TDEs should be detected.Following-up the brightest in quasi-real time would allow constraints to be made on the black holemass, spin and accretion regime and identify intermediate-mass black holes that are expected tobe hidden in faint, low-mass galaxies. We will discuss the advantages that such changes wouldhave on the follow-up of transients and TDEs.

Chapter 3

Variable MultiwavelengthEmitters and MultiwavelengthFacilities

20 Variable Multiwavelength Emitters and Multiwavelength Facilities

The Kepler/K2 Supernova Experiment

Geert Barentsen1, Jessie Dotson1

1Kepler/K2 Mission, NASA Ames Research Center, Moffett Field, California, USA

Many transient surveys tend to find supernovae only at or past maximum light. In contrast,NASA’s Kepler Space Telescope, now operating in its extended K2 mission, recently embarkedon an ambitious experiment to continuously monitor a sample of >20,000 nearby galaxies usinguninterrupted, high-precision, 30-minute cadence photometry. The goal of the experiment is tocapture dozens of supernovae from the very start of the explosions, allowing the tremendous amountof information contained in the early rise light curves to be recorded. For Type Ia supernova thedata is expected to help elucidate the trigger mechanism, while for Type II supernovae the curveshelp reveal the shock breakout. In this contribution I will present this new data set, which isfully public, and summarize the early science results. I will also highlight Kepler/K2’s recentobservations of AGN, CVs, Young Stars, and X-ray sources.

Time Domain X-Ray Astrophysics: ISS/TAO

Ehud Behar1, Jordan Camp2

1Technion, Israel2NASA, GSFC

The Transient Astrophysics Observer on Board the International Space Station (ISS/TAO) is aNASA mission selected for a concept study, with contributions from ISA. It will employ a wide fieldX-ray telescope in conjunction with a Gamma-ray Transient Monitor (GTM) Its primary goal isto observe electromagnetic counterparts of gravitational wave (GW) events emanating, e.g., fromneutron-star (NS) binary mergers, as soon as possible after the merger, and following a trigger fromGW instruments or from the GTM. The wide field imager will employ advanced Lobster optics ona fast slewing platform and observe several hundred square degrees at a time, thus tracking downthe GW source. The GTM will detect gamma-ray bursts (GRBs) in the half-sky above the ISSand provide sufficient directional information to trigger and point the WFI towards the source.The talk will present the ISS/TAO concept, main capabilities, and current status, as well as itsunique contribution to time domain astrophysics at high energies.

Variable Multiwavelength Emitters and Multiwavelength Facilities 21

Coordinated Multi-wavelength Observations of Transitional Millisecond Pulsars

Slavko Bogdanov1, Adam Deller2, James Miller-Jones3, Amruta Jaodand4, Anne Archibald4,Jason Hessels4, Alessandro Patruno5, Caroline D’Angelo5, Cees Bassa6

1Columbia University, New York, NY, USA2Swinburne University of Technology, Hawthorn, VIC, Australia

3Curtin University, Perth, WA, Australia4University of Amsterdam, Amsterdam, The Netherlands

5Leiden University, Leiden, The Netherlands6ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, The Netherlands

Within the past few years, three neutron star binaries have been observed to switch betweenaccreting and rotation-powered pulsar states, cementing the standard model for the formation ofrotation-powered millisecond pulsars via spin-up by accretion in a low-mass X-ray binary. Theseso-called transitional millisecond (tMSPs) pulsars exhibit intriguing behavior spanning from ra-dio frequencies to the GeV gamma-ray range. Multi-wavelength observations of tMSPs hold thepromise of providing fresh insight into the physics of accretion and shocks, as well as compact bi-nary evolution. I will present an overview of our extensive coordinated multi-wavelength observingcampaigns of confirmed and candidate tMSPs, as well as on-going surveys to uncover new systems.

The e-ASTROGAM space mission for MeV-GeV gamma-ray astrophysics

Stefano Ciprini1,2

1ASI Space Science Data Center, Rome, Italy2INFN Section of Perugia, Perugia, Italy

Future high-energy time-domain astronomy will not develop in a comprehensive, synergetic,powerful, serendipitous way, if a particularly important broad and multiple-physical ambient spec-tral window in the Universe is left unobserved. In this view e-ASTROGAM is a breakthroughobservatory space mission project, with large international interest, characterized by a detectorcomposed by a silicon tracker, calorimeter, and anticoincidence system, dedicated to the observa-tion of the Universe from 0.3 MeV to 3 GeV gamma-ray energies. The lower limit can be pushed aslow as 150 keV for the tracker and 30 keV for calorimetric detection. e-ASTROGAM dramaticallyimprove the COMPTEL, INTEGRAL and Fermi sensitivities. e-ASTROGAM is optimized for thesimultaneous detection of Compton and pair-producing photon events over such wide band, withunprecedented capabilities in gamma-ray continuum and line spectroscopy and imaging, large fieldof view sky survey, time-domain monitor, and polarization measurement, all opening a ultra-richand interdisciplinary science menu. e-ASTROGAM is the solution for the big problem of thenext two decades astronomy: the lack of observations in a wide photon energy band, placed be-tween those of the current/next XMM-Newton, Chandra, Swift, INTEGRAL, NuSTAR, eROSITA,HXMT, SVOM, IXPE, XARM, Athena, and other and the, above 40GeV, energy band of CTA.


The evolving jet spectrum of the neutron star X-ray binary Aql X-1 in transitionalstates during its 2016 outburst

Maria Diaz Trigo1, Diego Altamirano2

1ESO, Garching bein Muenchen, Germany2University of Southampton, Southampton, UK

I will report on quasi-simultaneous observations from radio to X-ray frequencies of the neutronstar X-ray binary Aql X-1 over accretion state transitions during its 2016 outburst. All the ob-servations show radio to millimetre spectra consistent with emission from a jet, with a spectralbreak from optically thick to optically thin synchrotron emission that decreases from ∼100 GHzto < 5.5 GHz during the transition from a hard to a soft accretion state. During the decay ofthe outburst, the jet spectral break is detected again at a frequency of ∼40-100 GHz. This is thefirst time that a change in the frequency of the jet break of a neutron star X-ray binary has beenmeasured, indicating that the processes at play in black holes are also present in neutron stars,thus supporting the idea that the internal properties of the jet rely most critically on the conditionsof the accretion disc and corona around the compact object, rather than the black hole mass orspin or the neutron star surface or magnetic field.

The nature of the soft X-ray excess in AGN

Chris Done1

1University of Durham

The origin of the soft X-ray excess in AGN is still controversial. I will review new constraintson its nature and geometry that come from both fast X-ray spectral-timing observations and fromlonger term multiwavelength monitoring campaigns.I will discuss how this component changes asa function of L/LEdd, and how it may be linked to the ’changing-look’ AGN phenomena, as seenin the disappearing BLR in Mkn 1018.


Studying optical and very-high-energy gamma-ray variability with ImagingAtmospheric Cherenkov Telescopes

Tarek Hassan1, Juan Abel Barrio2, Ralph Bird3, Jose Luis Contreras2, Juan Cortina4, MichaelDaniel5, John Hoang2, Jamie Holder6, Marcos Lopez Moya2, Luis Angel Tejedor2, Greg Richards6

1DESY2UCM-GAE

3UCLA4CIEMAT

5Smithsonian Astrophysical Observatory6University of Delaware

During the last two decades, the great success of space missions and the development andrefinement of new detection techniques from ground has allowed outstanding scientific results in thegamma-ray astronomy field. Imaging Atmospheric Cherenkov Telescopes are currently the mostsensitive instruments to detect very-high-energy gamma-ray photons (E > 50 GeV), especiallyexcelling in short time-scale observations required to study fast variability.

Additionally, as IACTs are sensitive to the Cherenkov light (UV/blue) and use photodetectorswith extremely short time responses, they are also able to perform simultaneous optical observa-tions. The large reflecting surface of these telescopes (larger than 100 m2) makes them world-classdetectors to study fast optical transient phenomena from the millisecond regime down to nanosec-ond scales with moderate angular resolution and wide field of view.

In this talk we will evaluate the capabilities of IACTs to study fast variability in both opticaland VHE ranges and report some of their excellent scientific results.

Compact binary millisecond pulsars: new views from X-ray and optical variability

Manuel Linares1,2

1UPC, Barcelona, Spain2IEEC, Barcelona, Spain

Compact binary millisecond pulsars (with orbital periods shorter than about a day) have be-come a sizeable and rapidly-growing pulsar population during the last decade. I will review theirthree main states, and the unique interplay they show between accretion- and rotation-poweredphenomena. I will also present recent results from our studies of optical and X-ray variability,including: i) our measurement of one of the highest pulsar masses found to date (2.27+0.17

−0.15 M⊙)and ii) the discovery of the brightest optical companion to a compact binary millisecond pulsar,in a 21-hr orbit.


Magnetar-like Activity and Radio Variability from High Magnetic Field PulsarJ1119- 6127

Walid Majid1, Aaron Pearlman2, Thomas Prince2

1JPL, Caltech2Caltech

X-ray and gamma-ray outbursts were recently observed from the high magnetic field pulsar PSRJ1119-6127, along with additional magnetar-like activity. We present results from a high frequencyradio monitoring campaign of PSR J1119-6127 at S-band (2.3 GHz) and X-band (8.4 GHz) with theDeep Space Network (DSN) 70 m antenna (DSS-43) in Canberra, Australia following these recentoutbursts. After an initial disappearance of radio pulsations, the S-band pulse profile evolvedfrom a multi-peaked structure into a single-peak over several weeks, which is unusual for radiopulsars. Bright, transient X-band pulsations were detected as the S-band pulse profile becamesingle-peaked, which led to a significant flattening of the spectral index to -0.4(1). This transitionis likely further evidence of magnetar-like behavior since this spectral index agrees remarkably wellwith measurements from other known radio magnetars, such as XTE J1810-1917, PSR J1622-4950,and SGR J1745-2900. PSR J1119-6127 is clearly a transitional object, and these observations mayprovide the missing evolutionary link between pulsars and magnetars.

Challenges of coordination and possible solutions

Jan-Uwe Ness1, Aitor Ibarra1, Celia Sanchez-Fernandez1, Erik Kuulkers1, Peter Kretschmar1,Jesus Salgado1, Emilio Salazar1, Matthias Ehle1, Carlos Gabriel1

1European Space Astronomy Centre

Over the last years, scientific demands for simultaneous observations using several observato-ries have substantially increased. The availability of other facilities is limited by various factors,primarily their celestial constraints, but also technical constraints (calibrations, maintenance) andhigh-priority time-critical observations of other targets. Telescope availability is communicatedto the public but in diverse ways without any standard format. Achieving simultaneous coveragewith multiple missions thus relies on effective communication of the respective planning teams,embedding coordinated observations in a systematic long-term planning approach.

We propose two services, defining an international standard in which visibility and planninginformation can be provided by all participating observing facilities. We plan to involve as manyfacilities as possible for agreeing on the standard that shall later be certified by the Virtual Obser-vatory (VO). Based on the services, clients can be developed to improve efficiency of coordinatedobservations.


Hardness Ratio cycles in AGN - classifying different states, and the possible XRBconnection

Uria Peretz1, Ehud Behar11Technion

The physics behind the dramatic and unpredictable X-ray variability of AGNs has eluded as-tronomers since it was discovered. We present an analysis of Swift/XRT observations of 44 AGNselected as heavily monitored objects. Change of Hardness Ratio (HR) with luminosity is measuredfor all objects in order to: 1. Classify different AGN according to their HR-L/L Edd (Luminosityover Eddington luminosity) relation. 2. Identify trends observed by combining the entire sample3. Compare trends with similar results in X-ray binaries. This work aims to improve on previousworks by collecting all AGN classified objects and uniformly analyzing them, comparing them ina phase diagram of HR and L/L Edd. In addition we compare results using a photon count basedHR definition and an energy based HR definition. Using energy units when defining hardnessratios results in a more clear classification of AGN types. In all cases we observe a clear dichotomybetween Seyferts and BL LACs. We provide schematic physical models to explain the observedscenarios. Finally, we find evidence for a possible cyclic behavior of Seyferts in the HR-L/L EddDiagram, possibly beginning in the BL LAC part of the phase diagram.

Optical precursors to X-ray binary outbursts

David Russell1, Dan Bramich1

1New York University Abu Dhabi, Abu Dhabi, UAE

Disc instability models predict that for X-ray binaries (XRBs) in quiescence, there should be abrightening of the optical flux prior to an X-ray outburst. Tracking the X-ray variations of XRBsin quiescence is generally not possible, so optical monitoring provides the best means to measurethe mass accretion rate variability between outbursts. With our regular Faulkes Telescope/LasCumbres Observatory (LCO) monitoring we are routinely detecting the optical rise of new XRBoutbursts before they are detected by X-ray all-sky monitors, helping to ensure continued moni-toring of the optical/X-ray sky. We present detections of an optical rise in several XRBs prior tooutbursts. Our current understanding of the quiescent variability in these high energy astrophys-ical objects is summarised. We show that it may be possible to predict when new outbursts mayoccur, by estimating the accumulation of matter in the disc from optical monitoring. Finally, weintroduce our new real-time data analysis pipeline, the ”X-ray Binary New Early Warning System(XB-NEWS)” which aims to detect and announce new XRB outbursts within a day of first opticaldetection. This allows us to trigger X-ray and multi-wavelength campaigns during the very earlystages of outbursts, to constrain the outburst triggering mechanism.


XMM-Newton study of the symbiotic binary systems in the Draco dwarf spheroidalgalaxy

Sara Saeedi1, Manami Sasaki21Institute of astronomy and astrophysics Tubingen, Germany

2Dr. Karl Remeis-Sternwarte, Erlangen Centre for Astroparticle Physics, Bamberg, Germany

We present the results of the study of symbiotic binary systems in the Draco dwarf spheroidalgalaxy (dSph) using 31 XMM-Newton observations. The sources have been classified on the basisof multi-wavelength studies of the counterparts in the optical, infrared and near-infrared surveys.The X-ray, UV, and optical long-term variability of the systems were simultaneously investigatedusing the data of X-ray cameras (EPICs) and the optical/UV monitor telescope (OM) onboardof XMM-Newton. The deep XMM-Newton observations allowed us to significantly analyse thespectrum of different types of symbiotic binaries. We have identified 15 symbiotic systems andcandidates Draco dSph. Out of these sources, 2 systems are classified as super-soft sources (typeα), with a spectrum that can be fitted with a blackbody model. 7 systems show soft X-rayemission mainly below 2.4 keV (Type β), which is consistent with a single or multiple componentsof collisionally ionised gas. One candidate also shows highly absorbed X-ray emission above 2.4keV (Type δ) and has a spectrum which can be fitted with a two-component model of opticallythick plasma.

Towards the SuperWASP - XMM stellar rotation-activity relation

Heidi Thiemann1, Andrew Norton1

1Department of Physical Sciences, The Open University, Walton Hall, Milton Keynes, U.K.

SuperWASP is the most successful ground-based survey for transiting exoplanets, having discov-ered more than 150 hot Jupiters. As a spin-off, data from the survey can also be used for in-depthstudies of variable stars. The SuperWASP archive contains high cadence light curves of more than30 million unique objects, up to 1 million of which have detectable photometric periodicities ontimescales from hours to years. The 3XMM-DR7 catalogue, the most recent data release of anotherbig survey, XMM-Newton, contains 727,790 X-ray source detections, relating to 499,266 uniqueX-ray sources.

We summarise the cross-correlation between the SuperWASP variable star catalogue and the3XMM-DR7 catalogue, which has detected 15,740 X-ray visible unique objects displaying pho-tometric variability, including sinusoidal variables, eclipsing binaries, and pulsators. This newcatalogue will, itself, be cross-correlated with Gaia Data Release 2 (Gaia DR2), giving the paral-laxes and proper motions, as well as light curves for 500,000 variable sources.

We look ahead to making use of this cross-correlation to complete the largest study of therotation-activity relation for main sequence stars - an important probe for the stellar dynamoprocess, and for fundamental information on the spin evolution of late-type stars.


Biases in Gamma-ray and MWL timing studies of AGN

Stefan Wagner11LSW, ZAH, U. Heidelberg, Germany

Most gamma-ray emitting AGN are variable and multiwavelength temporal studies provideinsights into acceleration and radiation mechanisms, source size, radiative re-processing and sourcestructure.

The gamma-ray band is very wide and is explored with very different techniques. In differentenergy bands very different biases affect temporal studies. Many of them are specific to the gamma-ray domain. The biases have significant implication for statistical analysis within the spectral rangecovered by a single facility, for comparisons between different gamma-ray facilities and for analysesof multiwavelength correlations between other High Energy bands.

The study characterizes the most significant biases and presents examples of potential errorsin AGN studies that are specific to the gamma-ray domain and correlations to the X-ray band.Astrophysical implications cover a wide range from AGN structure, acceleration processes, andfundamental physics.


Chapter 4

Timing from Accretion andEjection Phenomena

30 Timing from Accretion and Ejection Phenomena

Probing the inner accretion region with the deepest XMM-Newton observation of ahighgly variable AGN

William Alston1, Andrew Fabian1, Douglas Buisson1, Erin Kara2, Michael Parker3, AnneLohfink4, Phil Uttley5, Dan Wilkins6, Ciro Pinto1, Barbara De Marco7, Edward Cackett8,

Matthew Middleton9, Dom Walton1, Chris Reynolds1, Jiachen Jiang1

1Institute of Astronomy, Cambridge2Department of Astronomy, University of Maryland, College Park, Maryland 20742-2421, USA

3European Space Agency (ESA), European Space Astronomy Centre (ESAC), E-28691 Villanueva de laCanada, Madrid, Spain

4Montana State University, P.O. Box 173840, Bozeman, MT 59717-38405Astronomical Institute Anton Pannekoek, University of Amsterdam, Science Park 904, 1098XH,

Amsterdam, the Netherlands6Kavli Institute for Particle Astrophysics and Cosmology, Stanford University, Stanford, CA 94305, USA7Nicolaus Copernicus Astronomical Centre of the Polish Academy of Sciences, ul. Bartycka 18, 00-716

Warszawa8Department of Physics & Astronomy, Wayne State University, 666 W. Hancock St, Detroit, MI 48201,

USA9Department of Physics and Astronomy, University of Southampton, Highfield, Southampton SO17 1BJ, UK

The fast timing properties of accreting black hole light curves allow us to probe the directvicinity of black holes, the region most affected by strong gravity. We present an extensive X-ray variability analysis from a new 1.5 mega-second XMM-Newton VLP observation of the highlyvariable Seyfert 1 galaxy, IRAS 13224-3809. This is the longest observation taken to date on anearby variable AGN. This long observation has revealed complex underlying variability processes,displaying the first non-linear rms-flux relation in any accreting source. We will show modellingof the coronal and reverberation delays using GR ray tracing models. This allows us to buildup the most detailed picture to date of the inner X-ray emitting regions of AGN. We discuss theimplication of these results for accreting sources across the mass range.

The flickering jet of MAXI J1535-571

Maria Cristina Baglio1,2, David Russell11New York University of Abu Dhabi, Saadiyat Campus, P.O. Box 129188 Abu Dhabi, UAE

2INAF-Osservatorio Astronomico di Brera, via E. Bianchi 46, 23807 Merate (Lc), Italy

We present optical and infrared (REM, Faulkes telescope; VLT-VISIR) observations of the newblack hole candidate transient X-ray binary (BHB) MAXI J1535-571 during outburst.

The target is well detected in the mid-infrared, reaching a dereddened flux of >100 mJy, whichmakes MAXI J1535-571 the brightest mid-infrared BHB known so far.

At the beginning, the target shows an optical-NIR spectrum that is consistent with an opticallythin synchrotron power-law from a jet. After a certain epoch, the source faded considerably,the drop in flux becoming more evident at decreasing frequencies. Simultaneously, a significantsoftening of the X-ray spectrum, obtained with Swift and MAXI, occurred. We interpret this resultas due to the quenching of the jet, similar to the accretion-ejection coupling seen in other BHBs.

We also observe the source flaring in the infrared after the softening. All the detected activitycorrelates with X-ray hardness deviations.

We then show the first mid-IR variability study of a BHB on minute timescales. On some datesthe mid-IR flux of MAXI J1535571 varied by a factor of two in < 15 minutes, and on one datethere is a sudden decrease of the flux to undetectable levels.

Timing from Accretion and Ejection Phenomena 31

Disk Structure of Cataclysmic Variables and Broadband Noise Characteristics incomparison with XRBs

Solen Balman1

1METU, Dept. of Physics, 06800, Turkey

Flicker noise and its variations in accreting systems have been a diagnostic tool in understandingaccretion disk structure and state transitions. I will present broadband noise variations of nonmag-netic cataclysmic variables (CVs) in comparison with magnetic CVs extrapolating the comparisonsinto X-ray binaries, mostly in the X-ray wavelengths. CVs demonstrate band limited noise in theUV and X-ray energy bands (and also some optical), which can be adequately explained in theframework of the model of propagating fluctuations (Balman & Revnivtsev 2012, Balman 2014,2015). The detected frequency breaks in the nonmagnetic CVs are in the range (1-6) mHz inquiescence and indicates an optically thick disk truncation (i.e., transition) indicating existenceof hot flows in the inner regions. Analysis of other available data (e.g., SS Cyg, SU UMa, WZSge, Z Cha) reveal that during the outburst the inner disk radius moves towards the white dwarfand receeds as the outburst declines (with some exceptions) while changes in the X-ray energyspectrum is also observed. Cross-correlations between the simultaneous optical, UV and X-raylight curves show time lags consistent with truncated optically thick disk and inner disk hot flows.I will also discuss the hysteresis effects in nonmagnetic CVs.

X-Ray and mm-Wave Monitoring of Radio Quiet AGNs

Ehud Behar11Technion, Israel

X-ray and mm-wave observations have the potential of revealing the physics of gas in the in-nermost regions of AGNs, just before it accretes onto the black hole. X-ray and radio luminositieshave been shown to be correlated in radio quiet (RQ) AGNs. However their temporal behaviorare starkly different. While the X-rays can vary dramatically on short time scales of hours, radioemission at a few GHz is relatively stable over months or even years. If the radio emission isdue to synchrotron, it would be self absorbed at radio frequencies, but much less so at mm-wavefrequencies (100 GHz and more). To that end, it is beneficial to monitor RQ AGN variability inmm-waves, and compare it with X-rays variability. The talk will describe recent observations, andsuggest new ones, with contemporary and future instruments, which could shed new light on thenature of radio and mm-wave emission from these sources.


X-Ray Spectrum of RBS 315: Absorption or Intrinsic Curvature

Sivan Ben Haim1, Ehud Behar11Technion, Israel

X-ray absorption in high-redshift quasars is enigmatic because it remains unclear where in theuniverse is the absorbing gas. If absorption occurs near the host, it could help us understandthe universe at the early stages of galactic formation. We report on observations of one of thebrightest X-ray sources at a high redshift, RBS 315 (z=2.69), which is also a bright radio source(FSRQ). Despite previous analyses, no definite conclusion as to the source of the curvature in itsspectrum could be reached. We present observations by XMM-Newton (EPIC, RGS), Swift/XRTand Nustar. A statistical analysis of the spectrum yielded no clear results - the spectrum is as likelyto be absorbed as it is to be intrinsically curved. Variability provided an insight, and we find thatthe observed curvature of the spectrum of RBS 315 varied within a month, hence if an absorberis responsible for the curvature, it must be located near the host. Such an absorber should have ahigh column density, thus creating spectral lines in the spectrum, yet these are not discernible inthe RGS spectrum. By ruling this option out, we concluded that the curvature is intrinsic to thesource.

IGR J17329-2731: the birth of a symbiotic X-ray binary

Enrico Bozzo1

1Department of Astronomy, University of Geneva

I will report on the results of the multi-wavelength campaign carried out after the discovery ofthe INTEGRAL transient IGR J17329-2731. The optical data allowed us to identify the donor staras a late M giant at 2.7(+3.4,-1.2) kpc. The XMMNewton and NuSTAR data showed the presenceof a modulation with a period of 6680 s in the X-ray lightcurves of the source that we interpretedas the neutron star spin period. The broad-band X-ray spectrum showed the presence of a strongabsorption (∼5E23 cm−2) and prominent emission lines at 6.4 keV, and 7.1 keV. The presence ofan absorption feature at ∼21 keV suggests a cyclotron origin, measuring the neutron star magneticfield at ∼2.4E12 G. IGR J17329-2731 is thus a new symbiotic X-ray binary. As no X-ray emissionwas ever observed from the source by INTEGRAL during the past 15 yrs and considering thatsymbiotic X-ray binaries are known to be variable but persistent X-ray sources, we concluded thatINTEGRAL most likely caught the first detectable X-ray emission from IGR J17329-2731. TheSwift XRT monitoring performed up to 3 months after the discovery of the source, showed that itmaintained a relatively stable X-ray flux and spectral properties.


Using multiwavelength spectral variability to uncover the accretion structure inAGN

Douglas Buisson1

1Institute of Astronomy, University of Cambridge

AGN are powered by accretion onto a supermassive black hole in a system which includes a UVemitting disc and central X-ray emitting corona, as well as other material which may include anoutflowing wind. Variability of the X-ray emission both heats the disc, causing correlated changesin UV emission, and changes the amount of reflected X-ray emission. Recent studies comparingX-ray and UV variability have shown that in some sources the time lags between these bands arelonger than is predicted by the standard disc model. In other sources, including IRAS 13224-3809,the correlation is not observed at all. Using results from a sample of sources monitored withSwift and a large XMM program dedicated to IRAS 13224-3809, we will explore which physicalconditions could be responsible for extending or obscuring X-ray to UV lags and in particularwhether relativistic winds, as observed in IRAS 13224-3809, may have an influence.

Discovery of a new ULX pulsar in NGC 300

Stefania Carpano1, Frank Haberl1, Chandreyee Maitra1, Georgios Vasilopoulos11Max Planck Institute for Extraterrestrial Physics, Garching bei Munchen, Germany

Thanks to a very long and simultaneous observation of NGC 300 with XMM-Newton andNuSTAR between 2016 December 16 and 20, we discovered pulsations from the supernova impostorSN 2010da located in NGC 300, later identified as a B[e] high-mass X-ray binary. The pulse periodis changing from 31.71 s to 31.52 s from the start to the end of the observation, leading to a spin-uprate of −5.56 × 10−7 s s−1, which is extremely fast. The 0.3–30 keV unabsorbed luminosity is of4.7 × 1039 erg s−1 is much higher that what was initially reported in previous Swift, Chandra andXMM-Newton observations. Applying our best-fit model to the spectra, we find that the lower fluxfrom the archival XMM-newton observation of 2010 was caused by a larger amount of absorption,while the intrinsic luminosity was similar as seen in 2016. We conclude that the source is anothercandidate for the new class of ultraluminous X-ray pulsars.


23.8 h QPO in the Swift light curve of XMMU J134736.6+173404

Stefania Carpano1, Chichuan Jin1,2

1Max Planck Institute for Extraterrestrial Physics, Garching bei Munchen, Germany2National Astronomical Observatories (NAOC), China Academy of Sciences, Beijing, China

XMMU J134736.6+173404 is an X-ray source discovered serendipitously by XMM-Newton whichis now found to be spatially coincident with a Seyfert 2 galaxy, but presented once a very sharppersistent flux drop of a factor 6.5 within 1 h that is hard to relate to any AGN activity, due tothe short time scale. Thanks to a set of 29 Swift observations conducted from the 6 February tothe 23 May 2008, we discovered a twin peak quasi-periodic oscillations with periods of 23.82±0.07h and 71.44±0.57 h that we attribute to resonances of epicyclic frequencies. The AGN is radio-loud and the broadband SED modelling indicates a black hole with a mass of 2.8 × 107M⊙, thataccretes at an Eddington ratio of 0.008. QPOs for active galaxies have been reported so far inonly few cases, the most reliable one being from RE J1034+396 for which a 1 h periodicity hasbeen discovered analysing a 91 ks XMM-Newton observation. Twin peak QPOs with an observedfrequency ratio of 3:1 have not been reported so far for any AGN. From resonances models of theepicyclic frequencies we evaluate the different possible mass-spin relations.

First evidence of an X-Ray activity cycle on the young solar-analog Epsilon Eridanae

Martina Coffaro1, Beate Stelzer1, Jorge Sanz-Forcada2, Christian Schneider3, Uwe Wolter3,Marco Mittag3, Jeffrey Hall4, Travis Metcalfe5

1Institut fur Astronomie und Astrophysik, Tuebingen, Germany2Centro de Astrobiologa CSIC-INTA, Madrid, Spain

3Hamburger Sternwarte, Hamburg, Germany4Lowell Observatory, Flagstaff AZ, USA

5Space Science Institute, Boulder CO, USA

Chromospheric CaII activity cycles are frequently found in late-type stars, but their coronalX-ray counterparts are difficult to catch. The typical time scale of activity cycles goes from yearsto decades, probed by CaII monitoring campaigns. Therefore, long-lasting missions are neededto detect the coronal counterparts. XMM-Newton has so far detected X-ray cycles in four stars.We are now moving from the first detections to an exploration of the parameter space rulingdynamo cycles. As stellar variability has a known impact on the evolution of planets, a particularlyintriguing question is at what age (and at what activity level) X-ray cycles set in. I present here thefirst results of an ongoing XMM-Newton monitoring campaign for the young solar-analog EpsilonEridanae. At 500 Myr, it is one of the youngest solar-like stars with a known chromospheric CaIIcycle. The cycle lasts only 3 years, allowing to confirm or disprove the X-ray cycle in reasonabletime-scales. In our ongoing XMM-Newton campaign started in 2015, we find clear and systematicX-ray variability. I discuss these observations together with our contemporaneous CaII monitoringof the cycle and I put Epsilon Eridanae in the context of other stars with X-ray cycles.


Morfology of the fast variability in selected AGNs observed by XMM-Newton

Andrej Dobrotka1, Maximilian Stremy1, Pavol Bezak1

1Faculty of Materials Science and Technology, Slovak University of Technology, Trnava, Slovakia

Fast stochastic variability is a typical finger print of accretion process powering systems likecataclysmic variables, X-ray binaries and active galactic nuclei. This variability comprises ofsuperposed shots with characteristic time scales. Based on previous work on Cyg X-1 (Negoro 1994)and thanks to the Kepler data of cataclysmic variable MV Lyr we know that the characteristicPDS frequencies can be directly seen in the shot profile. We performed shot and PDS study ofselected AGNs observed by XMM-Newton and we searched for distinct shot patterns with timescales corresponding to the frequencies present in the PDSs. Some other features detected in CygX-1 are discussed in order to show signatures of common physical origin of the fast variability inX-ray binaries and AGNs.

Variability from weakly magnitized neutron stars in low-mass X-ray binaries tohighly magnitized neutron stars in ultra-luminous X-ray sources

Mehmet Hakan Erkut1, Kazim Yavuz Eksi11Physics Engineering Department, Faculty of Science and Letters, Istanbul Technical University, 34469,

Istanbul, Turkey

Quasi-periodic variability timescale of high-energy emission from neutron-star and black-holelow-mass X-ray binaries (LMXBs) extends from milliseconds to seconds, including kilohertz quasi-periodic oscillations (kHz QPOs) and low frequency QPOs. The recent discovery of QPOs fromultra-luminous X-ray sources (ULXs) with a frequency range from a few hertz to millihertz (mHz)has ignited a new discussion on the nature of the accreting compact object. The interpretation ofthese ULX QPOs in comparison with those observed in black-hole LMXBs has led to the conclusionthat the compact object is an intermediate-mass black hole (IMBH) in a high-mass X-ray binary(HMXB). The recent discovery of pulsations from several ULXs has, however, indicated that themajority of ULXs might consist of neutron stars accreting at super-critical rates. We herebyintroduce a unified picture for the interpretation of QPOs in terms of the magnetosphere-diskinteraction within the context of neutron stars accreting at sub-Eddington rates in LMXBs and atsuper-critical rates in HMXBs. We speculate that the main difference between kHz QPO sourcesin LMXBs and ULXs as mHz QPO sources in HMXBs could be the strength of the dipole magneticfield on the surface of the neutron star.


Simultaneous Kepler and XMM observations of bright flares in the Pleiades

Mario Giuseppe Guarcello1, Costanza Argiroffi1,2, Jeremy Drake3, Ettore Flaccomio1, JavierLopez-Santiago4, Giuseppina Micela1, Fabio Reale1,2, Salvatore Sciortino1, John Stauffer5,

Valsamo Antoniou3, Julian David Alvarado-Gomez3

1INAF - Osservatorio Astronomico di Palermo2Universita degli Studi di Palermo

3Harvard-Smithsonian Center for Astrophysics4Dpto. de Astrofısica y Cencias de la Atmosfera, Universidad Complutense de Madrid

5Spitzer Science Center (SSC), IPAC, California Institute of Technology

Flares are among the most powerful phenomena occurring in late-type stars. Stellar flares cannot be spatially resolved as we do on the Sun, and thus temporal analysis is the only tool availableto derive their physical properties. Furthermore, a multi-wavelength approach is desirable: Opticaland hard X-rays are mainly emitted from the footpoints of the flaring magnetic loops, while UVand soft X-rays emission from the dense heated plasma filling up the loops. Several possiblemechanisms for flare triggering and evolution are debated with important implications, given theimpact that UV and X-ray photons may have on circumstellar material and close planets.

I will present a combined X-ray (four XMM/Newton observations, between 50 ksec and 80 ksec)and optical (Kepler/K2, campaign 4) study of the most powerful flares observed in the 100 Myrsold stars in the Pleiades, aimed at constraining the energy released in the optical and X-ray bands,and the geometry and evolution of the flaring loops. I will also compare these flares to thoseobserved so far in stars at different age and evolutionary stages to derive an evolutionary patternof the energy budget released in optical and X-rays and other flare properties.

Phase resolved spectrum analysis of mHz QPOs in 4U 1636-53 using Hilbert-HuangTransform

Hung-En Hsieh1, Yi Chou1, Ka-Ho Tse1, Yi-Hao Su1

1Graduate Institute of Astronomy, National Central University, Taoyuan, Taiwan

We present the phase-resolved spectroscopy based on Hilbert-Huang Transform (HHT) for mil-lihertz quasi-periodic oscillations (mHz QPOs) in 4U 1636-536. This ∼8mHz QPO can be detectedabout several thousand seconds before type-I X-rat burst. It was interpreted as marginally stableburning on neutron-star surface. We used the HHT to extract the QPOs instantaneous phases, andconstructed its phase-resolved spectra for whole cycle. The spectral parameter modulations showthe neutron star surface temperature is likely positively correlated with the variation of neutronstar luminosity.


Global radio versus bolometric X-ray flux correlation in the black hole X-ray binaryGX 339–4

Nazma Islam1, Andrzej Zdziarski11Nicolaus Copernicus Astronomical Center, Warsaw, Poland

Compact radio jets are ubiquitous in stellar mass black hole binaries in their spectrally hardstate. The correlation between the radio emission from the compact jets and X-ray emission fromthe accretion disk around the black hole, is of major importance in understanding the nature ofaccretion disk- jet coupling in black hole X-ray binaries. Previous works investigating the radioversus X-ray emission correlation properties, used the narrow 3-9 keV or 1-10 keV X-ray energyband luminosity as proxy for accretion rate. However, the bulk of X-ray emission in the spectrallyhard state of black hole X-ray binaries, is emitted around 100 keV. We investigated the globalradio versus bolometric X-ray luminosity correlation for the black hole X-ray binary GX 339-4using RXTE observations. We have found that these correlations show an effect of hysteresis,previously found in the relationship between the X-ray hardness and flux, but not in the radioband. These correlations will provide new insights into the various accretion disk and jet ejectionmodels.

Spectral-Timing Models: The Key to XRB Accretion

Ra’ad Mahmoud1, Chris Done1

1Department of Physics, University of Durham, South Road, Durham, DH1 3LE

The nature of the accretion flow in Black Hole binaries in their low/hard state is highly con-troversial, as fitting to the time averaged energy spectra is degenerate. Potential models involvecontributions from a truncated disc/hot inner flow, and/or from the jet, and/or from highly rela-tivistic reflection. Addressing this degeneracy, we use the vital information contained in the fastvariability together with the spectrum. We build a quantitative model where density fluctuationspropagate down through a hot flow connected to a truncated disc to simultaneously fit to thespectrum, the power spectra in different energy bands, and the frequency-dependent lags betweenthese bands. Our models show the importance not just of the transition between the disc and hotflow, but the way the hot flow itself must be radially stratified in temperature/optical depth. Weshow how the fast spectral-timing data eliminate other potential models of the low/hard state,and hence how these spectral-timing techniques are the key to understanding the physical natureof the accretion flow.


High-density relativistic reflection as the origin of soft and hard X-ray excess inhighly-accreting AGN

Labani Mallick1, William Alston2, Michael Parker3, Ciro Pinto2, Andrew Fabian2

1Inter-University Centre for Astronomy and Astrophysics, India2Institute of Astronomy, University of Cambridge, United Kingdom3European Space Astronomy Centre (ESA/ESAC), Madrid, Spain

We perform spectral-timing studies of a highly-accreting AGN using data from a deep XMM-Newton observation and quasi-simultaneous NuSTAR and Swift observations. The broadband(0.3-50 keV) spectrum is characterized by a strong soft X-ray excess below ∼ 2 keV, one narrowFe Kα emission line at ∼ 6.4 keV, one broad, ionized Fe emission line at ∼ 6.8 keV and a hard X-rayexcess emission around 20-30 keV. We find that relativistic reflection from an ionized, high-densityaccretion disc, can simultaneously produce the soft excess, broad Fe line and hard X-ray excessemission from the source. At the lowest frequencies (≤ 6× 10−5 Hz), we find a hard lag where thedirect coronal emission dominated hard band (1.5-5 keV) lags behind the disc reflection dominatedsoft band (0.3-1 keV), while at higher frequencies, we detect a soft lag which is interpreted asa signature of X-ray reverberation from the accretion disc. The combined spectral and timinganalyses suggest that the soft X-ray excess emission results from the relativistic reflection off anionized, high-density accretion disc at around 3-20 gravitational radii, whereas the broad Fe lineand Compton hump originate from the relativistic reflection off the disc at around 1 gravitationalradius.

Complex Circumnuclear Structures in the Radio-Loud AGN Mkn 6 from X-rayAbsorption Variability

Alex Markowitz1,2, Beatriz Mingo3, Martin Hardcastle4

1Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Warsaw, Poland2UC San Diego, Center for Astrophysics and Space Sciences, La Jolla, USA

3The Open University, Milton Keynes, U.K.4University of Hertfordshire, Hertfordshire, U.K.

The Sy 1.5 AGN Mkn 6 is only the second RL AGN (besides Cen A) to exhibit strong line-of-sight X-ray absorption variability. It has multiple sets of radio bubbles indicating accretionactivity within last 1e5-6 years, and Kharb et al. (2006) gave evidence for a precessing jet ejectionaxis. Such a jet could interact with and churn up circumnuclear gas; the accretion structure thusmay not yet be fully stabilized. Here, we present preliminary results from simultaneous broadbandmulti-epoch NuSTAR/Suzaku and NuSTAR/Swift observations of Mkn 6 in 2015. We apply self-consistent torus models to infer the current geometry of the circumnuclear X-ray-absorbing and-reflecting gas, and apply our models to archival X-ray data, 1997-2009 to expand on the results ofMingo et al. (2011). We find evidence for a sustained zone of moderately-Compton thick clumpsnear the X-ray source, as well as Compton-thick reflecting gas out of the line of sight. We placeour results in the context of both radio-loud AGN and ”changing-look” Seyferts.


Rapid X-ray spectral variability observed in the star forming galaxy MCG–3–58–007

Gabriele Matzeu1, Valentina Braito2,3, James Reeves3, Paola Severgnini2, Roberto Della Ceca2,Claudia Cicone2, Michael Parker1, Maria Santos-Lleo1, Norbert Schartel1

1European Space Astronomy Centre (ESA/ESAC), E-28691 Villanueva de la Canada, Madrid, Spain2INAF, Osservatorio Astronomico di Brera

3Center for Space Science and Technology, University of Maryland Baltimore County

We report the result of a detailed analysis from a deep simultaneous 130 ks XMM-Newton &NuSTAR observation of the nearby (z = 0.0315) and bright starburst-AGN system: MCG–03–58–007. Rapid short-term X-ray spectral variability has been detected, which may be caused by twovariable zones of highly ionized fast (vw,1 ∼ 0.10c and vw,2 ∼ 0.35c) outflowing wind. Here we showthat such powerful outflow is launched from within a few 100Rg from the black hole, whose kineticoutput matches the prescription for significant feedback required by galaxy evolution models. Suchdramatic and fast variability of the wind, places MCG–3–58-007 among the unique objects suchas the luminous quasar PDS456 which is considered the prototype of fast disc-wind.

Mildly obscured AGN and the CXB: From averaged properties to individual sources

Christos Panagiotou1, Roland Walter11Astronomy Department, University of Geneva, Chemin d’ Ecogia 16, 1290 Versoix, Switzerland

The diffuse cosmic X-ray background (CXB) is the sum of the emission of discrete sources,mostly black-holes accreting matter in active galactic nuclei (AGN). The comparison of the CXBwith the spectra of individual sources is an important tool to check our knowledge of the AGNpopulation. High signal-to-noise average hard X-ray spectra, derived from more than a billionseconds of effective exposure time with the Swift/BAT instrument, indicated that mildly obscuredCompton thin AGN feature a strong reflection and contribute massively to the CXB. As a resultpopulation of Compton thick AGN larger than that effectively detected is not required, as no morethan 6% of the CXB flux can be attributed to them. The hard X-ray sensitivity of NuSTARallows to measure the primary X-ray continuum, the reflection and the iron K line emission, withunprecedented signal-to-noise. NuSTAR spectra of local Seyfert galaxies, confirm the link betweenreflection and obscuration statistically and in individual sources. The stronger reflection observedin mildly obscured AGN suggests that the covering fraction of the gas and dust surrounding theircentral engines is a key factor in shaping their appearance and confirms the need for a revision ofthe AGN unification model.


The X-ray continuum time-lags and intrinsic coherence in AGN

Iossif Papadakis1,2

1Physics Department, University of Crete, Greece2IESL, Foundation for Research & Technology (FORTH), Crete, Greece

I will present the results from a systematic analysis of the X-ray continuum time-lags andintrinsic coherence for ten X-ray bright and highly variable AGN. The continuum time-lags havea power-law dependence on frequency with a slope of ∼ −1, and their amplitude scales with thelogarithm of energy. We also find that their amplitude increases with the square root of the X-rayEddington ratio. Regarding the intrinsic coherence, we found that it is approximately constant atlow frequencies, and then decreases exponentially at frequencies higher than a characteristic ‘breakfrequency’. Both the low-frequency constant intrinsic-coherence value and the break frequency havea logarithmic dependence on the light-curve mean-energy ratio. Neither the low-frequency constantintrinsic-coherence value, nor the break frequency exhibit a universal scaling with either the centralblack hole mass, or the the X-ray Eddington ratio. I will discuss briefly implications of our resultson various theoretical models of AGN X-ray variability.

Rapid variability of ultra-fast outflows and timing prospects

Michael Parker11ESA/ESAC, Madrid, Spain

Variability of ultra-fast outflows has long been observed, but recently it has been seen ontimescales down to 1ks, and with both the velocity and ionization of the gas responding tothe X-ray source. The rapid variability and correlation with the continuum raid the possibility ofusing timing based techniques to study these outflows, both as a means of detecting them and asa probe of their physics. I will show that simple variability spectra can be used to detect spikesin variability from UFO absorption lines, and explore the potential uses of more advanced timingtechniques to directly measure the density of the gas and hence its location.


The rapid growth of black holes in the early Universe

Edwige Pezzulli1,2,3

1INAF-Osservatorio Astronomico di Roma2Universita’ di Roma La Sapienza

3INFN-Sezione di Roma

Observational searches for faint active nuclei at z > 6 have been extremely elusive. Interpretingthis lack of detections is crucial to improve our understanding of high-z supermassive black holes(SMBHs) formation and growth. We present a model for the emission of accreting BHs in theX-ray band, taking into account super-Eddington accretion, which can be very common in gas-richsystems at high-z . We compute the spectral energy distribution for a sample of active galaxiessimulated in a cosmological context. We find an average Compton-thick fraction of 45 per centand large typical column densities (NH ¿ 1023 cm2 ). However, faint progenitors are still luminousenough to be detected in the X-ray band of current surveys. Even accounting for a maximumobscuration effect, the number of detectable BHs is reduced at most by a factor of 2. In oursimulated sample, observations of faint quasars are mainly limited by their very low active fraction( 1 per cent), which is the result of short, supercritical growth episodes. To detect high-z SMBHsprogenitors, large area surveys with shallower sensitivities, such as XMM-LSS+XXL, are to bepreferred with respect to deep surveys probing smaller fields, such as CDF-S.

Long-term variability of high-mass X-ray binaries with MAXI

Jose Joaquın Rodes1, Tatehiro Mihara2, Jose Miguel Torrejon1, Mutsumi Sugizaki2, GracielaSanjurjo-Ferrın1, Guillermo Bernabeu1, Satoshi Nakahira3

1University Institute of Physics Applied to Sciences and Technologies, Alicante, Spain2Institute of Physical and Chemical Research (RIKEN), Wako, Japan3Institute of Space and Astronautical Science (ISAS), Tsukuba, Japan

In this work we present our long-term analysis of some X-ray binary sources observed by MAXI.We start to obtain its light-curves, then we estimate its orbital periods and finally derive the goodtime interval to extract orbital phase-resolved spectroscopy. Our data show an excellent coveragefor many orbits of the systems and extend over more than five years. Thus, the study of the X-rayspectrum from the neutron star at different orbital phases provides us the variability of the modelparameters we can use to compare with the different stellar wind accretion scenarios. This analysisstrategy allow us to study the permanent structures present in the stellar wind and circumsourceenvironment.


The Vast Potential of Exoplanet Hunting Satellites for High Energy Time DomainAstrophysics

Krista Lynne Smith1

1Stanford University

The unmatched photometric precision, monitoring baselines and rapid, even sampling ratesrequired by modern satellites designed for detecting the signal of transiting exoplanets are ideallysuited to a large number of applications in high energy astrophysics. These precision instrumentsare currently underutilized for high energy applications perhaps due simply to lack of intersectionalmarketing. I will exemplify this by discussing my results for AGN and accretion disks from Kepler,which show new and different properties than ground-based light curves, as well as summarizingother high energy results from Kepler/K2. I will then explain how future missions like TESS andPLATO can be used very effectively for studies of accretion onto compact objects, especially whenused in conjunction with X-ray timing instruments like XMM, Swift, and NICER.

Radiative transfer in the neutron star atmosphere: reflection model

Ekaterina Sokolova-Lapa1,2, Sebastian Falkner1, Jorn Wilms1, Fritz-Walter Schwarm1

1Dr. Karl Remeis-Observatory & ECAP, University of Erlangen-Nuremberg, Bamberg, Germany2Sternberg Astronomical Institute, M. V. Lomonosov Moscow State University, Moscow, Russia

We present the new theoretical model for calculating the reflection of the radiation from theneutron star surface illuminated by the accretion column for high-mass X-ray binaries. We calcu-late the trajectories of photons emitted from the column onto the neutron star surface consideringthe gravitational light bending to obtain the external boundary condition for radiative transfersimulation in the neutron star atmosphere. The equation of the radiative transfer is solved usingthe Feautrier method for two photon polarization modes with partial angle and frequency redis-tribution, taking into account the possibility of the mode conversion. The resulting spectrum istreated as the additional to the direct column one flux component. The intention of the currentlydeveloping model is to investigate the effects of the reflection from the neutron star surface on thespectrum characteristics of the X-ray pulsars.


Energy dependent timing studies of the low-hard state of black hole X-ray binarieswith XMM-Newton

Holger Stiele1, Albert Kong1

1National Tsing Hua University, Institute of Astronomy, Guangfu Road 101, Sect. 2, Hsinchu, Taiwan

Almost all low mass black hole X-ray binaries are transient sources. During outburst most ofthese sources evolve from the low-hard state through intermediate state(s) into the high-soft stateand then return to the hard state at lower luminosity. However, there are outbursts that remainin the hard state. By fitting mean X-ray spectra, one studies the time-averaged spectral shapeof a source, learning nothing about how the individual spectral components vary with respect toeach other in time. This variability can be studied using covariance spectra. Here we present theresults of a comprehensive study of covariance spectra for a sample of black hole X-ray binariesobtained during the two outburst patterns outlined above and discuss what covariance spectracan tell us about outburst evolution. Furthermore we present covariance ratios obtained during asoft-to-hard transition of an outburst and show that their evolution is consistent with increaseddisc instabilities.

Super-Eddington X-ray pulsars in the Magellanic Clouds

Lee Townsend1

1University of Cape Town, Cape Town, South Africa

In 2016, SMC X-3 underwent an long-duration X-ray outburst of extreme brightness. It’sluminosity peaked at 1.2 x 1039 erg/s, making it one of the closest known ultra-luminous X-ray sources (ULX). SMC X-3 is one of a small number of very nearby X-ray binaries to reachsuper-Eddington accretion rates, making them important systems in understanding more distantultra-luminous X-ray pulsars (ULP). I will discuss the properties of SMC X-3 during this luminousoutburst, emphasising the similarities and differences between SMC X-3 and more distant, ’bonafide’ ULPs. These nearby systems can potentially be used as tools to better understand theaccretion physics occurring in more distant ULPs and ULX sources in general.


Fast quasi-periodic oscillations in magnetic cataclysmic variables

Lucile Van Box Som1,2, Jean-Marc Bonnet-Bidaud2, Clotilde Busschaert1, Andrea Ciardi3,Emeric Falize1,2, Martine Mouchet4

1CEA-DAM-DIF, F-91297 Arpajon, France2CEA/DRF - CNRS - Universite Paris Diderot, IRFU/DAp Centre de Saclay, F-91191 Gif-sur-Yvette,

France3LERMA, Observatoire de Paris, PSL Research University, CNRS, Sorbonne Universites, UPMC Univ.

Paris 06, F-75005 Paris, F4LUTH, Observatoire de Paris, PSL Research University, CNRS, Univ. Paris Diderot, USPC, F-92195

Meudon, France

Several Polars (accreting magnetic white dwarfs rotating synchronously with the orbital motion)have revealed 1-Hz quasi-oscillations (QPOs) in the optical, while upper limits only have beenderived from XMM-Newton observations. These oscillations are thought to be associated withthe existence of hydro-radiative instabilities in the post-shock zone which induce shock heightoscillations with a period of the order of the post-shock cooling time scale. The cooling is dominatedeither by bremsstrahlung or cyclotron radiation, depending on the magnetic field and the accretionrate values.

We will review the current observational properties of QPOs in Polars and compare them withthe radiative properties of our numerical 1D simulations of the structure and dynamics of thepost-shock region relevant to the physical parameters of polars exhibiting QPOs (masses, accretionrate, magnetic field). Though large uncertainties exist for these parameters, we will show that thestandard model of column instability remains insufficient to account for the observations, thusleaving the origin of QPOs as an opened question. Different solutions, such as a fragmentation ofthe accretion flow, are proposed, which require 3D simulations.

Living on the edge: the RWI in accretion disk around Kerr Black hole

Peggy Varniere1, Frederic Vincent2, Fabien Casse1

1APC, AstroParticule et Cosmologie, Universite Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire deParis, Sorbonne Pari

2Observatoire de Paris / LESIA,

The Rossby-Wave Instability (RWI) has been proposed to be at the origin of the high-frequencyQPOs observed in black-hole system. Here we are presenting the first full GR simulation of theinstability around a Kerr black-hole which allow us to explore the impact of the spin on theinstability. Those simulations, coupled with a full GR ray-tracing, allow us to directly compareour simulation with observables we get in X-ray.


NOVAs: a Numerical Observatory of Violent Accreting systems

Peggy Varniere1, Fabien Casse1, Frederic Vincent21APC, AstroParticule et Cosmologie, Universite Paris Diderot, CNRS/IN2P3, CEA/Irfu, Observatoire de

Paris, Sorbonne Pari2Observatoire de Paris / LESIA,

Here we are presenting NOVAs, a Numerical Observatory of Violent Accreting systems, whichcouples a GR AMR MPI (GRAMRVAC) code able to follow accretion around a Kerr Black-holewith the ray-tracing code GYOTO. Together, they allow us to test different models by runningthe simulation and obtaining spectral energy distribution and power-density spectrum from whichwe can extract the same observables as in for ”real” observations, hence making it a NumericalObservatory.

Multiwavelength variability of GX 339-4 during its 2015 outburst decay

Federico Vincentelli1,2,3, Piergiorgio Casella2, Kieran O’Brien4, Thomas Maccarone5, PhilUttley6, Tomaso Belloni3, Rob Fender7, David Russell8, Barbara De Marco9, Julien Malzac10

1DiSAT, Universita’ dell’insubria, Como,Italy2INAF Osservatorio Astronomico di Roma, Monte Porzio Catone, Italy

3INAF, Osservatorio Astronomico di Brera, Merate, Italy4Department of Physics, Durham University, Durham, UK

5Department of Physics& Astronomy Texas Tech University, Lubbock TX, USA6Anton Pannekoek Institute for Astronomy, University of Amsterdam, Amsterdam, Netherlands

7University of Oxford, Oxford, UK8New York University, Abu Dhabi, UAE

9Nicolaus Copernicus Astronomical Center, Warsaw, Poland10Nicolaus Copernicus Astronomical Center, Warsaw, Poland

We present the results from the first multi-wavelength fast-photometry campaign of a black-holetransient outburst decay. We observed GX 339-4, simultaneously in X-rays and near-infrared, athigh time resolution during the OIR re-brightening at the end of its 2015 outburst. We find timingproperties that are significantly different from the ones found during past multi-wavelength obser-vations. The cross correlation function has a strongly asymmetric shape, with an anti-correlationpeak at IR positive lags. The measured lags show a clear dichotomy between low and high fre-quencies. While at frequencies lower than 0.3Hz an approximately constant phase lag of -π/2 ispresent, for frequencies higher than 1Hz the lag inverts sign and a 0.1 s time lag emerges. Suchbehaviour can be fully explained in terms of internal shocks models. We also report the detectionin the IR Fourier power spectrum of a type-C quasi-periodic oscillation at 0.1 Hz, with evidenceof a X-ray QPO at the same frequency. Further IR high time resolution observations taken inthe same period, without simultaneous X-ray coverage, reveal that the IR QPO evolves, with acentroid frequency passing from 0.2 to 0.05 Hz in less than a week.


Chapter 5

Triggers of Variability:Magnetism, Shocks, Companions

48 Triggers of Variability: Magnetism, Shocks, Companions

General Relativity through OJ 287 light curve timing

Stefano Ciprini1,2, Mauri Valtonen3,4, Staszek Zola5,6, Arti Goyal51ASI Space Science Data Center, Rome, Italy

2INFN Section of Perugia, Perugia, Italy3Finnish Centre for Astronomy with ESO, University of Turku, Kaarina, Finland

4Tuorla Observatory, Department of Physics and Astronomy, University of Turku, 21500 Kaarina, Finland5Astronomical Observatory, Jagiellonian University, Krakow, Poland6Mt. Suhora Observatory, Pedagogical University, Krakow, Poland

The proper understanding of blazars, and other AGNs, time-domain variability at the variouselectromagnetic energy bands is an important goal of multifrequency astrophysics, where peri-odicity represents a peculiar and controversial phenomenology claimed for very few objects. Thewell-known BL Lac object OJ 287 (PKS 0851+202, z=0.306) is not only a high-variable extragalac-tic source with hints for recurrent pseudo-cyclical optical outbursts, but it also represents a case ofsubstantial intensive and extensive (long-term) multi-frequency time-domain data archive. Undera post-Newtonian General Relativity approach OJ 287 can be modeled as a binary supermassiveblack hole system, with a spinning primary and a non-spinning secondary, assuming the primaryhas an accretion disk which is impacted by the secondary at specific times. The model clockingof optical, UV, X-ray light curves provides clues on several General Relativity properties of thesystem, including spin, precession and energy losses by radiation of nano-Hz gravitational waves.This rich time series database on OJ 287 allowed us also a deeper variability power spectrumanalysis, across the electromagnetic spectrum.

Fast X-ray flares and quiescent emission from the quadruple system GT Muscae

Lorenzo Ducci1, Santina Piraino1, Long Ji1, Andrea Santangelo1, Juergen Schmitt2, CarloFerrigno3, Enrico Bozzo3

1IAAT, University of Tuebingen2Hamburger Sternwarte, Universitaet Hamburg

3ISDC, Versoix, University of Geneva

GT Muscae is a quadruple system hosting an RS CVn binary that shows a highly variable X-rayemission. We present a work based on the entire public archival INTEGRAL data set (exposuretime: 11 Ms; energy range: 3-40 keV) which covers the period 2003-2017, and on the recent XMM-Newton observation of June 2016. The WFC BeppoSAX data set (energy range: 2-28 keV), whichcovers the period 1997-2001 with an exposure time of about 0.85 Ms, is explored as well. The aimsof this work are to study the temporal variability and spectral properties of GT Muscae and inparticular its thermal component and to detect and constrain the non-thermal hard X-ray emissioncomponent. In our preliminary work, we detected 11 bright flares which reached X-ray luminositiesof 1E33 erg/s, about 20 times brighter than the low luminosity level of the source. In three cases,we detected with the ISGRI instrument hard X-ray emission up to 40 keV. We discuss the resultsin the framework of the current models proposed for the X-ray emission from RS CVn stars.

Triggers of Variability: Magnetism, Shocks, Companions 49

Is there any Correlation between Radiative Outbursts and Timing Irregularities inMagnetars?

Chin-Ping Hu1, C.-Y. Ng1

1Department of Physics, The University of Hong Kong

Magnetars are strongly magnetized pulsars and they occasionally show violent radiative out-bursts. They also often exhibit glitches, which are sudden changes in the spin frequency. It wasfound that some glitches were associated with outbursts but their connection remained unclear.We present a systematic study to identify any statistical correlations between them. We foundthat the glitch size of magnetars showed a wide distribution, different from the distribution of theVela-like recurrent glitches but consistent with the high end of that of normal pulsars. Except forthe outbursts from newly determined transient magnetars, a glitch is likely a necessary conditionfor an outburst but not a sufficient condition because only 30% of glitches were associated withoutbursts. In the outburst cases, the glitches tend to have larger sizes in both the spin frequencyand the spin-down rate compared to the unassociated ones. We argue that a larger glitch is morelikely to trigger the outburst mechanism, either the reconfiguration of the magnetosphere or thedeformation of the crust, or vice versa. A more frequent and deeper monitoring of magnetars isnecessary for further investigation of their connection.

Seven years in the cyclic coronal life of iota Hor

Jorge Sanz-Forcada1, Beate Stelzer2,3, Martina Coffaro2

1Centro de Astrobiologia (CSIC-INTA), Madrid, Spain2Institut fur Astronomie und Astrophysik, Tuebingen, Germany3INAF - Osservatorio Astronomico di Palermo, Palermo, Italy

XMM-Newton has been used to monitor the corona of ι Hor during seven years. The presence ofa previously known chromospheric activity cycle of 1.6 yr has been confirmed. Activity cycles arecommonly found among late type stars through the chromospheric Ca II emission. Their coronalcounterpart, however, remains elusive in most cases, despite of the clear X-ray cycle observed inthe solar corona, spanning as much as 1.7 dex in Lx. Here we present the final results of this longterm monitoring, where we clearly identify a quite stable coronal cycle of similar periodicity. ιHor, with an age of ∼600 Myr and spectral type F8V, represents a young solar analogue at theage at which life appeared on Earth

50 Triggers of Variability: Magnetism, Shocks, Companions

Calibrating the time-evolution of the X-ray emission of M dwarfs

Beate Stelzer1,2, Ignasi Ribas3, Diego Lorenzo de Oliveira4, Laura Venuti1, Richard Saxton5

1Institut fuer Astronomie und Astrophysik. Universitaet Tuebingen, Germany2INAF - Osservatorio Astronomico di Palermo, Italy

3Institut de Ciencies de l’Espai, Bellaterra, Spain4Instituto de Astronomia, Universidade de Sao Paulo, Brazil

5ESAC, Madrid, Spain

The time-evolution of the X-ray emission of M stars is fundamental for our understanding ofstellar dynamos and the irradiation of planet atmospheres with high-energy photons. However,the (X-ray) activity - age relation is still unconstrained, mainly due to the difficulty in the agedetermination. Our approach is to determine the evolution of X-ray luminosity (L x) and X-ray plasma temperature (T x) with age for M dwarfs, observing M stars in wide pairs with awhite dwarf that (through its progenitor and cooling age) serves as chronometer for a reliableage constraint. We present XMM-Newton and Chandra observations of 14 such systems spanningages of 1-7 Gyrs. Our study reveals that some old M dwarfs display unexpectedly strong X-rayemission. Due to the high sensitivity of the observations we could analyse the X-ray spectrum forsome of the M stars. This has allowed us to derive a relation between coronal temperature andflux - to our knowledge for the first time for M stars with known age.

Chapter 6

Explosive Astrophysics/FastAstrophysics

52 Explosive Astrophysics/Fast Astrophysics

The Transient High Energy Sky and Early Universe Surveyor (THESEUS)

Lorenzo Amati1, Paul O’Brien2, Diego Gotz3, Enrico Bozzo4, Christopher Tenzer51INAF - OAS Bologna, Italy2University of Leicester, UK

3CEA - IRFU, Universite Paris - Saclay, France4University of Geneva, Switzerland5University of Tuebingen, Germany

The Transient High-Energy Sky and Early Universe Surveyor (THESEUS) is a mission conceptdeveloped in the last years by a large European consortium, with interest in prospective partici-pation by research groups in USA and other non-European countries. As detailed in Amati et al.2017 (arXiv:1710.04638) and Stratta et al. 2017 (arXiv:1712.08153), THESEUS aims at exploitinghigh-redshift Gamma-Ray Bursts for getting unique clues to the early Universe (star formation rateand metallicity evolution up to redshift 10-12, Pop III stars, sources and physics of re-ionization,faint end galaxy luminosity function) and, being an unprecedentedly powerful machine for thedetection, accurate location and redshift determination of all types of GRBs (long, short, high-z, under-luminous, ultra-long) and many other classes of transient sources and phenomena, atproviding a substantial contribution to multi-messenger astrophysics and time-domain astronomy.Under these respects, THESEUS will show a beautiful synergy with the large observing facilitiesof the future, like E-ELT, TMT, SKA, CTA, ATHENA, in the electromagnetic domain, as wellas with next-generation gravitational-waves and neutrino detectors, thus enhancing importantlytheir scientific return. Moreover, it will also operate as a flexible IR and X-ray observatory, thusproviding an even larger involvement of the scientific community.Coordinated X-ray and Radio Observations of the Repeating Fast Radio Burst FRB

121102

Slavko Bogdanov1, Paul Scholz2, Jason Hessels3, Ryan Lynch4, Laura Spitler5, Cees Bassa6,Geoff Bower7, Sarah Burke-Spolaor8, Bryan Butler9, Shami Chatterjee10, James Cordes10, Kelly

Gourdji3, Victoria Kaspi11, Casey Law12, Benito Marcote13

1Columbia University, New York, NY, USA2Dominion Radio Astrophysical Observatory, Penticton, BC, Canada

3University of Amsterdam, Amsterdam, The Netherlands4Green Bank Observatory, Green Bank, WV, USA

5Max-Planck-Institut fur Radioastronomie, Bonn, Germany6ASTRON, Netherlands Institute for Radio Astronomy, Dwingeloo, The Netherlands

7Academia Sinica Institute of Astronomy and Astrophysics, Hilo, HI, USA8West Virginia University, Morgantown, WV, USA

9National Radio Astronomy Observatory, Socorro, NM, USA10Cornell University, Ithaca, NY, USA

11McGill University, Montreal, QC, Canada12University of California, Berkeley, CA, USA

13Joint Institute for VLBI ERIC, Dwingeloo, The Netherlands

FRB 121102, discovered with the Arecibo radio telescope, is the only known repeating fastradio burst source. Its extragalactic nature was unambiguously established via sub-arcsecondlocalization using the VLA along with Gemini and Hubble optical observations, which identifiedthe host as a faint, low-metallicity, star-forming dwarf galaxy at redshift z=0.193. Recent radiopolarimetry revealed that the FRB source resides in an extreme magneto-ionic environment. Inan attempt to constrain the nature of the underlying source, we have undertaken X-ray observingcampaigns with XMM-Newton, Chandra, and NuSTAR in coordination with radio observations ofFRB 121102 to search for X-ray burst as well as persistent counterparts. I will present the resultsof these observations and discuss them in the context of the host environment of this FRB and ofpossible sources of fast radio bursts in general. I will conclude with a review of future prospectsfor high energy studies of FRBs using existing and future facilities.

Explosive Astrophysics/Fast Astrophysics 53

Disk-jet alignment in Tidal Disruption Events: hints from Swift J1644+57

Sudip Chakraborty1, Sudip Bhattacharyya1, Chandrachur Chakraborty2

1Tata Institute of Fundamental Research, Mumbai, India2Kavli Institute for Astronomy and Astrophysics at Peking University, Beijing, China

An important problem of astrophysics is whether the jet from an accreting black hole is alignedwith the black hole spin axis or the accretion disk angular momentum vector. An answer to thisquestion can provide important information about the jet triggering mechanism, disk-jet coupling,and the high energy radiation mechanisms in a black hole system. Tidal Disruption Event (TDE)of a star by a super massive spinning black hole provides a unique astrophysical laboratory to studythe jet alignment through the possibility of Lense-Thirring precession of the jet. In this work, weinvestigate the Swift XRT light curve of the most well sampled jetted TDE, Swift J1644+57. Inthe thick disk regime of the light curve, we estimate, using a known optimistic method and a newconservative method developed by us, the tilt angle of the jet with respect to the black hole spinaxis as a function of the black hole spin parameter. We find that the previously reported dips areless likely to be caused by Lense-Thirring precession, i.e., the jet in Swift J1644+57 is more likelyto be aligned with the black hole spin axis.

Multiple X-ray bursts and the model of a spreading layer of accreting matter overthe neutron star surface

Sergei Grebenev1, Ivan Chelovekov1

1Space Research Institute, Moscow

We report the detection with INTEGRAL/JEM-X of series of close type I X-ray bursts consistingof two or three events with a recurrence time much shorter than the characteristic time of matteraccumulation needed for a thermonuclear explosion to be initiated on the neutron star surface. Weshow that such series of bursts are naturally explained in the model of a spreading layer of accretingmatter over the neutron star surface in the case of a sufficiently high accretion rate (correspondingto a mean luminosity Ltot > 4 × 1036 erg/s). In this model matter is accumulated in two high-latitude ring zones. When the first explosion occurs in one of the zones the flame propagates witha velocity of the deflagration wave to another zone and ignites its matter. The existence of triplebursts requires some refinement of the model - the importance of a central ring zone is shown. Inthe standard model of a spreading layer no infall of matter in this zone is believed to occur. Themodel explains also the observed enhancement of the burst generation rate by luminous burstersover the rate expected for the case of complete burning of matter accumulated between the bursts.


X-ray observations of Tidal Disruption Events in the era of Time DomainAstronomy

Erin Kara1

1University of Maryland

Tidal Disruption Events, where a star gets ripped apart by the strong tidal forces of a super-massive black hole, create an impulse of accretion, thus providing a unique opportunity to probeaccretion physics at its extremes, all while revealing properties of a population of dormant super-massive black holes. X-rays broke open the field of TDE astronomy, through initial discoveries withthe ROSAT All-Sky Survey, and subsequent discoveries with the XMM-Newton Slew Survey andthe Swift Burst Alert Telescope. In recent years, large optical time domain surveys have expandedthe field, finding TDEs soon after the initial disruption. Several of these optical discovered TDEshave been followed up in detail with pointed X-ray telescopes, like Swift, Chandra and XMM-Newton. In this talk, I will present a few of the exciting X-ray results, including the discoveriesof ultrafast outflows in two super-Eddington TDEs. I will highlight some of the open questions inthe field, and how future X-ray missions will revolutionize TDE studies in the 2020s.

Two Distinct-Absorption X-Ray Components from Type IIn Supernovae: Evidencefor Asphericity in the Circumstellar Medium

Satoru Katsuda1, Keiichi Maeda2

1Saitama University2Kyoto Univerisity

We present multi-epoch X-ray spectral observations of three Type IIn supernovae (SNe) 2005kd,2006jd, and 2010jl, acquired with XMM-Newton, Chandra, Suzaku, and Swift. Previous extensiveX-ray studies of SN 2010jl have revealed that X-ray spectra are dominated by hard thermal emis-sion, likely arising from a very hot plasma heated by a forward shock propagating into a massivecircumstellar medium (CSM). Interestingly, an additional soft X-ray component was required toreproduce the spectra at a period of 1-2 yr after the SN explosion. Its origin remained an openquestion. We find a similar soft X-ray component from the other two SNe IIn as well. Herewe present a new interpretation for the origin of this component; it is thermal emission from aforward shock, directly reaching us from a void of the dense CSM. Namely, the soft and hard com-ponents are responsible for the heavily- and moderately-absorbed components, respectively. Theco-existence of the two components with distinct absorptions as well as the delayed emergence ofthe moderately-absorbed X-ray component would be evidence for asphericity of the CSM. Basedon our X-ray spectral analyses, we estimate the radius of the torus-like CSM to be on the order of5e16 cm.


Identifying the XMM-Newton slew variable source population and the implicationfor Einstein Probe

Dongyue Li1, Richard Saxton2, Weimin Yuan1

1National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China2XMM SOC, ESAC, Apartado 78, 28691 Villanueva de la Canada, Madrid, Spain

The Einstein Probe is a small mission dedicated to time-domain astronomy to monitor the sky inthe soft X-ray band. It has similar sensitivity to that of the XMM-Newton slew survey (XMMSL)and will carry out systematic survey and characterization of high-energy transients. A catalogueof variable sources in the soft X-ray band is very important to EP. By comparing the 0.2-2 kevflux in the XMMSL observation to that in RASS (Rosat All Sky Survey), we have got a catalogueof 301 variable sources, which have varied more than a factor of 10. We did the identification withmulti-wavelength catalogue and got the category distribution. Among these sources, 2 of themare Cvs (Or candidate CVs), 15 are X-ray binaries, 67 are galaxies (5 TDEs), 56 are QSO/AGNand 119 are stars. We will talk about scientific goals of EP and the properties of the sources inthe variable source catalogue got from XMMSL. Implications of this catalogue for future missions(especially EP) will be discussed.

Searching for fast transients in XMM-Newton data

Ines Pastor Marazuela1, Natalie Webb1

1IRAP - Toulouse, France

The variability of X-ray detections in the 3XMM catalogue is explored through their fractionalvariability and chi-squared tests. However, some sources may show very short duration outbursts,resulting in few X-ray counts and thus having insufficient counts over a long observation to bedetected. Examples of such objects are distant and thus strongly redshifted faint short gamma-ray bursts that last less than two seconds, the electromagnetic counterparts of gravitational waveevents. Alternatively these could be type-I X-ray bursts in distant galaxies, or possibly X-raycounterparts to fast radio bursts (FRBs).

Building on existing software, I am developing an algorithm to automatically search XMM-Newton data for new sources that may have shown very short outbursts, but which are drownedout by the background noise summed over the whole observation. Searching for new objects inshort time bins throughout the duration of the observation may be one way to identify thesesources.

Here I will present the variability tests and results of the most interesting variable sourcesdiscovered. This code could be used to conduct automatic searches across observations to searchfor gravitational wave event counterparts as well as other fast transients.


Observations of tidal disruption events: past, present and future

Richard Saxton1, Andrew Read2, Stefanie Komossa3, Kate Alexander4, Pauline Lira5, IainSteele6

1XMM SOC, ESAC, Madrid2University of Leicester

3MPifR, Bonn4Harvard-Smithsonian Center for Astrophysics, Cambridge

5Universidad de Chile, Observatorio Astronomico Nacional Cerro Calan, Santiago6Liverpool John Moores University

The tidal disruption of a star by a nuclear supermassive black-hole was predicted in the 1970sand first confirmed by soft X-ray flares seen from quiescent galaxies in the ROSAT all-sky survey.Similar events have continued to be found in XMM-Newton and Chandra data and more recentlyflares in large-area hard X-ray, UV and optical transient surveys have also been attributed tothe same phenomenon. Each of these spectral components, sometimes complemented by radioand IR activity, have their own timescale and possibly physical mechanism. Current models andsimulations revolve around trying to explain how the energy released by the fall back of stellardebris in the gravitational well of the black hole is converted into radiation in each wave band.We provide an overview of the current state of knowledge on tidal disruption events, highlightingthe outstanding questions: what is the connection between UV and X-ray emission?, why are jetsrarely formed?, what determines whether an event is X-ray or optically bright ? We look at theobservations which are needed to make further breakthroughs in the field and assess the optimumfollow-up strategies needed for events discovered in future large survey missions such as eRositaand LSST.

Fast extragalactic transients in the XMM-Newton archive

Andrea Tiengo1,2, Giovanni Novara1,2, Andrea De Luca2, Ruben Salvaterra2, Andrea Belfiore2,Martino Marelli2

1IUSS Pavia2INAF, IASF-Milano

Thanks to the analysis of the full XMM-Newton archive within the EXTraS project, we identifieda large number of transient X-ray sources with a duration spanning from several minutes to a fewhours. Although most of them are flares from relatively nearby stars, some of the shortest bursts arevery likely powerful extragalactic events. In particular, through the measurement of the redshiftof its host galaxy, we could estimate the luminosity of one of these events and interpret it asthe X-ray flare likely from a core-collapse supernova. Our sensitivity to this kind of events hasbeen estimated through detailed simulations and can be used to constrain their rate in the localUniverse.


A network of optical telescopes dedicated to the early follow-up of multimessengertriggers

Damien Turpin on behalf of the GWAC team1, Sarah Antier2, Alain Klotz3,4, Nicolas Leroy2,En-wei Liang5, Xiang-Gao Wang5, Zi-Gao Dai6, Xiang-Yu Wang6, Yuan-Gui Yang7, Bertrand

Cordier8, Damien Dornic9, Bo-Bing Wu10, Cyril Lachaud11

1National Astronomical Observatories/Chinese Academy of Science 20A Datun Road, Beijing, 100012,China

2LAL, Univ. Paris-Sud, CNRS/IN2P3, Universite Paris-Saclay, F-91898 Orsay, France3Universite de Toulouse, IRAP 14 Av. Edouard Belin, F-31000 Toulouse France

4Institut de Recherche en Astrophysique et Planetologie (IRAP), UPS-OMP, Toulouse, France5Department of Physics and GXU-NAOC Center for Astrophysics and Space Sciences, Guangxi University,

Nanning 530004, China6School of Astronomy and Space Science, Nanjing University, Nanjing, 210093, China

7School of Physics and Electronic Information/Information College, Huaibei Normal University, Huaibei235000, China

8CEA Saclay, DSM/IRFU/Service d’Astrophysique 91191 Gif-sur-Yvette, France9Aix Marseille Univ, CNRS/IN2P3, CPPM, Marseille, France

10Institute of High Energy Physics/CAS, 19B YuquanLu, Beijing, 100049 ,China11Astroparticule et Cosmologie (APC), 75013 Paris, France

By multiplying close exhanges between various facilities from different astrophysical communities(gravitational wave-GW-, astroparticle, electromagnetic), the study of the multimessenger time-domain astronomy has deeply changed our way of observing the sky. The time-domain astronomyhas brought new challenges as it requires to quickly answer to multimessenger alerts with a goodsensitivity and sometimes with an instrument able to cover large error boxes. In the next fewyears, the dramatic increase of the number of multimessenger alerts will make their follow-up evenmore complex since it will require smart strategies to filter the triggers, to fully characterise the(numerous) candidates and to schedule efficient early and late follow-ups. The optimisation of theperformances of each facility is a need to guarantee the best scientific return. In this contribution,we present the strategy we have developped with a network of optical telescopes located in Chinato quickly follow-up LIGO/Virgo GW and GRB triggers. The results obtained during the GW-O2follow-up campaign and from our current observational program to catch the early optical afterglowcounterpart from the Gamma-ray Bursts will be also shown. Finally, we will discuss our plan tosignificantly extend this network and our strategy for the next GW-O3 campaign.

58 Name Index

Name Index

Alexander, Kate, 56Alston, William, 30, 38Altamirano, Diego, 22Alvarado-Gomez, Julian David, 36Amati, Lorenzo, 52Antier, Sarah, 57Antoniou, Valsamo, 36Archibald, Anne, 21Argiroffi, Costanza, 4, 36

Baglio, Maria Cristina, 30Baines, Deborah, 16Balman, Solen, 31Barentsen, Geert, 20Barrio, Juan Abel, 23Bassa, Cees, 21, 52Behar, Ehud, 20, 25, 31, 32Belanger, Guillaume, 17Belfiore, Andrea, 56Belloni, Tomaso, 45Ben Haim, Sivan, 32Bernabeu, Guillermo, 41Bezak, Pavol, 35Bhattacharyya, Sudip, 53Bird, Ralph, 23Bogdanov, Slavko, 21, 52Bogdanovic, Tamara, 4Bonnet-Bidaud, Jean-Marc, 44Bosnjak, Zelika, 9Bower, Geoff, 52Bozzo, Enrico, 32, 48, 52Braito, Valentina, 39Bramich, Dan, 25Buisson, Douglas, 30, 33Burke-Spolaor, Sarah, 52Busschaert, Clotilde, 44

Butler, Bryan, 52

Cackett, Edward, 30Camp, Jordan, 20Carpano, Stefania, 33, 34Casella, Piergiorgio, 45Casse, Fabien, 44, 45Chakraborty, Chandrachur, 53Chakraborty, Sudip, 53Chatterjee, Shami, 52Chelovekov, Ivan, 53Chernenko, Anton, 14Chomiuk, Laura, 14Chou, Yi, 36Ciardi, Andrea, 44Cicone, Claudia, 39Ciprini, Stefano, 21, 48Coe, Malcolm, 14Coffaro, Martina, 34, 49Coley, Joel, 14Contreras, Jose Luis, 23Corbet, Robin, 14Cordes, James, 52Cordier, Bertrand, 57Cortina, Juan, 23Costantini, Elisa, 9

D’Agostino, Daniele, 15D’Angelo, Caroline, 21Dai, Zi-Gao, 57Daniel, Michael, 23De Luca, Andrea, 15, 56De Marco, Barbara, 5, 30, 45Della Ceca, Roberto, 39Deller, Adam, 21Descalzo, Miguel, 17

59

60 Name Index

Diaz Trigo, Maria, 22Dobrotka, Andrej, 35Done, Chris, 22, 37Dornic, Damien, 57Dotson, Jessie, 20Drake, Jeremy, 36Dubus, Guillaume, 14Ducci, Lorenzo, 48

Edwards, Philip, 14Ehle, Matthias, 24Eksi, Kazim Yavuz, 35Erkut, Mehmet Hakan, 35Esposito, Paolo, 9

Fabian, Andrew, 30, 38Falize, Emeric, 44Falkner, Sebastian, 42Fender, Rob, 45Ferrigno, Carlo, 48Flaccomio, Ettore, 36Freyberg, Michael, 17Fuerst, Felix, 5

Gabriel, Carlos, 17, 24Giuliani, Andrea, 9Gotz, Diego, 52Gourdji, Kelly, 52Goyal, Arti, 48Grebenev, Sergei, 53Guarcello, Mario Giuseppe, 36

Haberl, Frank, 15, 33Haggard, Daryl, 6Hall, Jeffrey, 34Hardcastle, Martin, 38Hassan, Tarek, 23Hessels, Jason, 21, 52Hoang, John, 23Hodgkin, Simon, 6Holder, Jamie, 23Hsieh, Hung-En, 36Hu, Chin-Ping, 49Huppenkothen, Daniela, 7

Ibarra, Aitor, 17, 24Islam, Nazma, 37

Jaodand, Amruta, 21Ji, Long, 48Jiang, Jiachen, 30Jin, Chichuan, 34Jin, Ruolan, 15

Kuhnel, Matthias, 16Kara, Erin, 30, 54Kaspi, Victoria, 52Katsuda, Satoru, 54Klotz, Alain, 57Komossa, Stefanie, 56Kong, Albert, 15, 43Kretschmar, Peter, 16, 17, 24Krishnan, Saikruba, 16Kuulkers, Erik, 24

Lopez-Santiago, Javier, 36Lachaud, Cyril, 57Law, Casey, 52Leroy, Nicolas, 57Li, Dongyue, 55Liang, En-wei, 57Linares, Manuel, 23Lira, Pauline, 56Lohfink, Anne, 30Lopez Moya, Marcos, 23Lorenzo de Oliveira, Diego, 50Lusso, Elisabeta, 7Lynch, Ryan, 52

Maccarone, Thomas, 45Maeda, Keiichi, 54Mahmoud, Ra’ad, 37Maitra, Chandreyee, 33Majid, Walid, 24Mallick, Labani, 38Malzac, Julien, 45Marcote, Benito, 52Marelli, Martino, 56Markowitz, Alex, 16, 38Martin, Pierrick, 14Matzeu, Gabriele, 39McBride, Vanessa, 14Mereghetti, Sandro, 9Merin, Bruno, 16

Name Index 61

Metcalfe, Travis, 34Micela, Giuseppina, 36Middleton, Matthew, 8, 30Mihara, Tatehiro, 41Miller-Jones, James, 21Mingo, Beatriz, 38Mittag, Marco, 34Mouchet, Martine, 44

Nakahira, Satoshi, 41Nandikotkur, Giridhar, 17Ness, Jan-Uwe, 24Ng, C.-Y., 49Norton, Andrew, 26Novara, Giovanni, 56

O’Brien, Kieran, 45O’Brien, Paul, 52

Panagiotou, Christos, 39Papadakis, Iossif, 40Parker, Michael, 30, 38–40Pastor Marazuela, Ines, 55Patruno, Alessandro, 21Pearlman, Aaron, 24Peretz, Uria, 25Petroff, Emily, 8Pezzulli, Edwige, 41Pinto, Ciro, 30, 38Pintore, Fabio, 9Piraino, Santina, 48Poppenhaeger, Katja, 9Prince, Thomas, 24

Read, Andrew, 56Reale, Fabio, 36Reeves, James, 39Reynolds, Chris, 30Ribas, Ignasi, 50Richards, Greg, 23Rodes, Jose Joaquın, 41Russell, David, 25, 30, 45

Saeedi, Sara, 26Sala, Gloria, 10Salazar, Emilio, 24Salgado, Jesus, 16, 24

Salvaterra, Ruben, 9, 15, 56Sanchez-Fernandez, Celia, 24Sanjurjo-Ferrın, Graciela, 41Santangelo, Andrea, 48Santos-Lleo, Maria, 39Sanz-Forcada, Jorge, 34, 49Sasaki, Manami, 26Saxton, Richard, 17, 50, 55, 56Schartel, Norbert, 39Schmitt, Juergen, 48Schneider, Christian, 34Scholz, Paul, 52Schwarm, Fritz-Walter, 42Schwarzenberg-Czerny, Aleksander, 16Sciortino, Salvatore, 10, 36Severgnini, Paola, 39Smith, Krista Lynne, 42Sokolova-Lapa, Ekaterina, 42Spitler, Laura, 52Stauffer, John, 36Steele, Iain, 56Stelzer, Beate, 34, 49, 50Stevens, Jamie, 14Stiele, Holger, 43Stremy, Maximilian, 35Strader, Jay, 14Su, Yi-Hao, 36Sugizaki, Mutsumi, 41

Tanvir, Nial, 11Tejedor, Luis Angel, 23Tenzer, Christopher, 52Thiemann, Heidi, 26Tiengo, Andrea, 9, 15, 56Torrejon, Jose Miguel, 41Townsend, Lee, 14, 43Tse, Ka-Ho, 36Turpin, Damien, 57

Uttley, Phil, 16, 30, 45

Valtonen, Mauri, 48Van Box Som, Lucile, 44Varniere, Peggy, 44, 45Vasilopoulos, Georgios, 33Venuti, Laura, 50

62 Name Index

Vianello, Giacomo, 9Vincent, Frederic, 44, 45Vincentelli, Federico, 45

Wagner, Stefan, 27Walter, Roland, 11, 39Walton, Dom, 30Wang, Xiang-Gao, 57Wang, Xiang-Yu, 57Watson, Mike, 15Webb, Natalie, 18, 55Wilkins, Dan, 30Wilms, Jorn, 15, 16, 42Wolter, Uwe, 34Wu, Bo-Bing, 57

Yang, Yuan-Gui, 57Yuan, Weimin, 55

Zdziarski, Andrzej, 37Zola, Staszek, 48

Documents

Time-Domain Astronomy: A High Energy View · 2018-08-09 · Hernndez, Aitor Ibarra, Eleni Kalfountzou, Jan-Uwe Ness, Richard Saxton, Norbert Schartel, Michael Smith, Ana Willis. Contents